Prevalence of personal weight control attempts in adults: a systematic review and meta-analysis

Ceftriaxone reverses diet-induced deficits in goal-directed control

RATIONALE

Obesity is associated with numerous health risks and ever-increasing rates are a significant global concern. However, despite weight loss attempts many people have difficulty maintaining weight loss. Previous studies in animals have shown that chronic access to an obesogenic diet can disrupt goal-directed behavior, impairing the ability of animals to flexibly adjust food-seeking behavior following changes in the value of earned outcomes. Changes in behavioral control have been linked to disruption of glutamate transmission in the dorsal medial striatum (DMS), a region critical for the acquisition and expression of goal-directed behavior.

OBJECTIVES

The goal of this study was to test whether ceftriaxone, a beta-lactam antibiotic shown elsewhere to upregulate the expression of the glutamate transporter GLT-1, would improve goal-directed control following long-term exposure to an obesogenic diet.

METHODS

Male and female rats were given access to either standard chow or chow plus sweetened condensed milk (SCM) for 6 weeks. Access to SCM was ended and rats received daily injections of either ceftriaxone or saline for 6 days. Rats were then trained to press a lever to earn a novel food reward and, finally, were assessed for sensitivity to outcome devaluation. Histological analyses examined changes to GLT-1 protein levels and morphological changes to astrocytes, within the DMS.

RESULTS

We found that ceftriaxone robustly restored goal-directed behavior in animals following long-term exposure to SCM. While we did not observe changes in protein levels of GLT-1 in the DMS, we observed that SCM induced changes in the morphology of astrocytes in the DMS, and that ceftriaxone mitigated these changes.

CONCLUSIONS

These results demonstrate that long-term access to a SCM diet impairs goal-directed behavior while also altering the morphology of astrocytes in the DMS. Furthermore, these results suggest that ceftriaxone administration can reverse the impairment of goal-directed behavior potentially through its actions on astrocytes in decision-making circuitry.

The association of body mass index variability with cardiovascular disease and mortality: a mediation analysis of pooled cohorts

Aim

We aimed to investigate the effect of BMI variability on CVD and mortality and to explore the mediation effects of the main cardiovascular risk factors contributing to this association.

Method

Participants aged 40-65 years were pooled from three cohort studies(ARIC [Atherosclerosis Risk in Communities], MESA [Multi-ethnic Study of Atherosclerosis], and TLGS [Tehran Lipid and Glucose Study]. We employed root mean squared error of the fractional mixed model to calculate BMI variability in the measurement period. In the event assessment period, the hazard ratios for CVD and mortality were estimated using Cox proportional hazard regression models. In the next step, the mediation and interaction effects of fasting plasma glucose, total cholesterol, and systolic blood pressure were determined.

Results

A total of 19073 participants were included in this pooled analysis. During a median of 20.7 years of follow-up, 3900 (20.44%) CVD and 6480 (33.97%) all-cause mortality events were recorded. After adjusting for potential confounders, BMI variability was linked to the 1.3 (1.2-1.4) and 1.7 (1.6-1.8) increased risk of CVD and mortality, respectively. Fasting plasma glucose mediated approximately 24% and 8% of the effect of BMI variability on CVD and mortality, respectively. However, systolic blood pressure and total cholesterol did not have mediation effects in this association.

Conclusion

High BMI variability is independently associated with the development of CVD and mortality. This association is partly mediated through fasting plasma glucose. Modern cardiometabolic therapies that lower fasting glucose may reduce the risk of future CVD and mortality in individuals with high BMI variability.

Prepregnancy dieting and obstetrical and neonatal outcomes: Findings from a national surveillance project in the United States

PROBLEM AND BACKGROUND

Women with overweight or obesity are recommended to lose weight before pregnancy. Dieting is one of the most used weight control strategies. However, the health implications of dieting before pregnancy remain unclear.

AIM

To evaluate the associations of dieting during the year before pregnancy with obstetrical and neonatal outcomes, including gestational weight gain (GWG), gestational diabetes, low birthweight, macrosomia, small-for-gestational-age infants (SGA), large-for-gestational-age infants (LGA), and preterm birth.

METHODS

This study analyzed data from the Pregnancy Risk Assessment Monitoring System (PRAMS), which is a surveillance project in the United States that collects data on maternal health before, during, and after pregnancy. Women who participated in PRAMS phase 7 with a prepregnancy body mass index ≥25 kg/m2 and a singleton birth were eligible. Statistical analyses included logistic regressions and post-hoc mediation analysis (Sobel Test).

FINDINGS

A total number of 51,399 women were included in the analysis. Women who self-reported prepregnancy dieting (42.8 %) had lower odds of SGA (adjusted odds ratio [aOR]: 0.87; 95 % CI: 0.79-0.97), and higher odds of excessive GWG vs adequate GWG (aOR: 1.42; 95 % CI: 1.32-1.52), gestational diabetes (aOR: 1.12; 95 % CI: 1.02-1.22), and LGA (aOR: 1.18; 95 % CI: 1.08-1.28). Furthermore, the association between prepregnancy dieting and LGA was mediated by excessive GWG (Sobel Test z-value = 5.72, p < 0.01).

DISCUSSION AND CONCLUSION

This analysis revealed that prepregnancy dieting was associated with several adverse consequences, including excessive GWG, gestational diabetes, and LGA infants. Findings contribute to an improved understanding of the perinatal implications of prepregnancy dieting.

Food choices for weight loss: what dietary strategies would people use?

Previous observational research showed that one of the most common strategies used to lose weight is to avoid or restrict the consumption of specific food items. However, the question of how people behave and implement strategies in actual decision-making situations involving food choices for weight loss purposes remains inconclusive. This experimental study using a food buffet aimed to examine people's different dietary strategies and motives for selecting foods for an entire day for weight loss purposes compared with a normal-day (ND) food selection. A total of 111 participants (55 % women) had to choose foods for both a ND and a weight loss day (WLD) (within-study design). Kilocalories and nutrients were calculated based on the weights of the foods selected, and food choice motives were assessed using a questionnaire. The results showed that for weight loss purposes, the participants selected more vegetables (both sexes) and unsweetened beverages (only men) while reducing their choices of high-fat and high-energy products (both sexes). Participants' food choices in both conditions (ND and WLD) differed from the official nutrition recommendations. They chose less carbohydrates and fibres and more fat and sugar than recommended. Health, kilocalories and nutrient content (carbohydrates, sugar, fat and protein) were more important food choice motives for weight loss purposes than for a ND food selection, while taste became less important. In conclusion, the participants appeared to be well capable of implementing several appropriate dietary strategies. Further research is needed to explore strategies to help them maintain these dietary changes over the long term.

Self-identified strategies to manage intake of tempting foods: cross-sectional and prospective associations with BMI and snack intake

OBJECTIVES

Individuals often use self-directed strategies to manage intake of tempting foods, but what these strategies are and whether they are effective is not well understood. This study assessed the frequency of use and subjective effectiveness of self-directed strategies in relation to BMI and snack intake.

DESIGN

A cross-sectional and prospective study with three time points (T1: baseline, T2: 3 months and T3: 3 years). At T1, demographics, frequency of use and subjective effectiveness of forty-one identified strategies were assessed. At T2 and T3, current weight was reported, and at T2 frequency of snack intake was also recorded.

SETTING

Online study in the UK.

PARTICIPANTS

Data from 368 participants (Mage = 34·41 years; MBMI = 25·06 kg/m2) were used for analysis at T1, n = 170 (46·20 % of the total sample) at T2 and n = 51 (13·59 %) at T3.

RESULTS

Two strategy factors were identified via principal axis factoring: (1) diet, exercise, reduction of temptations, and cognitive strategies, and (2) planning, preparation and eating style. For strategy 1, frequency of use, but not subjective effectiveness, was positively related to BMI at T1. Subjective effectiveness predicted an increase in BMI from T1 and T2 to T3. No relationship to snack intake was found. For strategy 2, frequency of use was negatively related to BMI at T1. Neither frequency of use nor subjective effectiveness were related to changes in BMI over time, but subjective effectiveness was negatively correlated with unhealthy snack intake.

CONCLUSION

Self-directed strategies to reduce the intake of tempting foods are not consistently related to BMI or snack intake.

Food reward associations with motivational eating behavior traits and body mass index in Portuguese former elite athletes

BACKGROUND

Motivational eating behavior traits (i.e. eating motivations and intuitive eating) have an important role in body weight regulation, as do food reward processes. Their associations might help explain different responses to food stimulus in the current environment but have never been explored. This study's primary goal was to investigate food reward associations with eating motivations, intuitive eating dimensions and body mass index in former Portuguese elite athletes with overweight/obesity. As a first step, a cultural adaptation of the Leeds Food Preference Questionnaire (LFPQ) was created and validated in an online-surveyed Portuguese sample.

RESULTS

Step 1: Analysis from an online survey (N = 348; 69.8% female) conducted to validate the food images from the cultural adaptation of the LFPQ showed that most food images were properly recognized in terms of their fat and sweet content by the Portuguese population, except for some savory items. Step 2: Regarding our primary analysis in 94 former elite athletes with overweight/obesity, self-determined motivations to regulate eating and (to a lower extent) more body-food congruent choices (both markers for healthier eating behaviors) were associated with more favorable food reward outcomes, as opposed to non-self-determined motivations. Less emotional (more intuitive) eaters presented higher implicit wanting for low-fat sweet foods compared to more emotional eaters.

CONCLUSION

These findings suggest LFPQ usefulness to evaluate food preferences and detect relevant associations between food reward and motivational eating behavior traits in former elite athletes with overweight/obesity. Health professionals are encouraged to create need-supportive environments that foster self-determined motivations and help individuals make healthier food choices. © 2023 Society of Chemical Industry.

The Physiological Effects of Weight-Cycling: A Review of Current Evidence

PURPOSE OF REVIEW

There is a common perception among the public that yo-yo dieting, defined as repeated cycles of weight loss followed by weight regain, results in accumulation of fat in the body and lower metabolic rate, thus hindering subsequent attempts to lose weight. We evaluated the effects of weight-cycling on body weight and body mass index (BMI), body composition including fat mass (FM) and lean body mass (LBM), and resting metabolic rate (RMR), by systematically reviewing existing scientific literature.

RECENT FINDINGS

Twenty-three cross-sectional and cohort studies (including subjects with a history of weight-cycling compared to those without such history) and interventional studies (evaluating physiological effects during one or more cycles of weight loss and regain) were identified, conducted in generally healthy adults across various age groups, races, and both genders, who had normal weight, overweight, or obesity. Eighteen studies investigated the association between weight-cycling and body weight or BMI, and thirteen of them found no significant association. Fifteen out of twenty studies also found no increase in FM, and none of eighteen studies found a decrease in LBM. Twelve out of fourteen studies reported no adverse changes in RMR either. The overwhelming majority of evidence suggests that weight-cycling (yo-yo effect) is not associated with any adverse effects in body weight, body composition, and metabolic rate. Accordingly, healthy individuals who struggle with overweight or obesity should not be discouraged from repeated attempts to lose the excess weight.

Associations between adverse childhood experiences and history of weight cycling

Background

Adverse childhood experiences (ACEs) predict obesity onset; however, the relationship between ACEs and history of weight cycling has not been adequately explored. This gap is problematic given the difficulty in weight loss maintenance and the impact of ACEs on obesity development, chronicity, and associated weight stigma. The objective of this study was to examine associations between self-reported history of ACEs and weight cycling in a sample of weight loss treatment-seeking adults with overweight/obesity.

Methods

The number of participants in the analyzed sample was 78, mostly white educated adult women (80% female, 81% Caucasian, 75% ≥ bachelor's degree) with excess adiposity enrolled in the Cognitive and Self-regulatory Mechanisms of Obesity Study. ACEs were measured at baseline using the ACEs Scale. History of weight cycling was measured using the Weight and Lifestyle Inventory that documented weight loss(es) of 10 or more pounds.

Results

Higher ACE scores were associated with a greater likelihood of reporting a history of weight cycling. Participants with four or more ACEs had 8 times higher odds (OR = 8.301, 95% CI = 2.271-54.209, p = 0.027) of reporting weight cycling compared with participants with no ACEs. The association of weight cycling for those who endorsed one to three ACEs was not significant (OR = 2.3, 95% CI = 0.771-6.857, p = 0.135) in this sample.

Conclusions

The role of ACEs in health may be related to associations with weight cycling. Results indicated that those who reported four or more ACEs had significantly higher odds of reporting weight cycling compared with those with no ACEs. Further research is needed to further explore how ACEs predict the likelihood of weight cycling, which may be prognostic for sustained weight loss treatment response and weight stigma impacts.

Comparing self-reported energy intake using an online dietary tool with energy expenditure by an activity tracker

OBJECTIVE

The aim of this study was to compare self-reported total energy intake (TEI) collected using an online multiple-pass 24-h dietary recall tool (Intake24) with total energy expenditure (TEE) estimated from Fitbit Charge 2-improved algorithms in adults from the NoHoW trial (12-mo weight maintenance after free-living weight loss).

METHODS

Bland-Altman plots were used to assess the level of agreement between TEI and TEE at baseline and after 12 mo. The ratio of TEI to TEE was also calculated.

RESULTS

Data from 1323 participants (71% female) was included in the analysis (mean ± SD: age 45 ± 12 y, body mass index 29.7 ± 5.4 kg/m2, initial weight loss 11.5 ± 6.5 kg). The TEI was lower than TEE on average by 33%, with limits of agreement ranging from -91% to +25%. Men, younger individuals, those with higher body mass index, those with the greater weight loss before enrollment, and those who gained weight during the study underestimated to a greater extent.

CONCLUSIONS

These findings contribute to the ongoing research examining the validity of technology-based dietary assessment tools.

Weight Loss Attempts Increased in Korean Adults from 2005 to 2021, Excluding Those with Obesity

Background: Studies on trends in the proportions of past-year weight loss attempts among Asian adults are limited. Our hypotheses were that trends in the proportions would increase and sociodemographic, weight, and health-related factors would be associated with these attempts. Methods: Using data from the Korea National Health and Nutrition Examination Survey 2005-2021, this study evaluated the trends and their related factors among Korean adults. Complex sample design analyses were applied to the data of 80,160 adults. Results: The weighted proportion of past-year weight loss attempts increased from 35.2% in 2005 to 41.3% in 2021. The proportion of past-year weight loss attempts increased for individuals with nonobese body mass index (BMIs) (<25 kg/m2), decreased for males with obese BMIs (≥25 kg/m2), and did not change for females with obese BMIs. A multivariate-adjusted model showed that the proportion of weight loss attempts decreased for males and increased for females over the 16-year period [odds ratio (OR) (95% confidence interval): males, 0.993 (0.988-0.998); females, 1.013 (1.009-1.017)]. The OR of weight loss attempts was higher for females, younger individuals, and those with higher economic status, higher BMIs, self-perceived larger body shapes, self-rated better health, and chronic diseases. These characteristics decreased the odds of individuals with obese BMIs making no weight loss attempts. Conclusions: The proportion of past-year weight loss attempts increased over the 16-year period among all participants, but a declining trend was observed for those with obesity. In addition to BMI, socioeconomic factors, subjective perceptions of body shape, and health-related factors were related to weight loss attempts.

A Qualitative Model of Weight Cycling

Weight cycling is a likely consequence of striving to lose weight after internalizing body image ideals, making upward social comparisons, and experiencing weight stigma. Despite weight cycling's potential physical and psychological consequences, the interplay of weight cycling, social pressures, and experienced and internalized stigma have not been qualitatively explored. Thus, through in-depth interviews of 36 weight-cycling adults, this study sought to understand how people negotiate weight cycling. Interviews informed the development of a qualitative model of weight cycling, which was derived from a theory-neutral inductive analysis. The model's stages included entering the cycle, undergoing the cycle, and challenging the cycle. Participants were triggered to enter the cycle due to weight stigma caused by social pressures. Within the cycle, interviewees internalized weight stigma and engaged in disordered weight management behaviors. Some participants challenged the cycle by becoming more self-aware and mitigating their toxic dieting behaviors. However, it was very difficult, if not impossible, for many to fully exit weight cycling and the restraints of previous weight management thinking and patterns. Our investigation underscores the seriousness of weight cycling and suggests ways to combat weight cycling on both macro and individual levels. It may also be useful to consider weight cycling as disordered eating in hopes of shifting society's dangerous focus on rapid weight loss.

Oligofructose-Enriched Inulin Consumption Acutely Modifies Markers of Postexercise Appetite

Enhancing the effectiveness of exercise for long-term body weight management and overall health benefits may be aided through complementary dietary strategies that help to control acute postexercise energy compensation. Inulin-type fructans (ITFs) have been shown to induce satiety through the modified secretion of appetite-regulating hormones. This study investigated the acute impact of oligofructose-enriched inulin (OI) consumption after exercise on objective and subjective measures of satiety and compensatory energy intake (EI). In a randomized crossover study, following the completion of a 45 min (65-70% VO2peak) evening exercise session, participants (BMI: 26.9 ± 3.5 kg/m2, Age: 26.8 ± 6.7 yrs) received one of two beverages: (1) sweetened milk (SM) or (2) sweetened milk + 20 g OI (SM+OI). Perceived measures of hunger were reduced in SM+OI relative to SM (p = 0.009). Within SM+OI, but not SM, plasma concentrations of GLP-1 and PYY were increased and acyl-ghrelin reduced from pre-exercise to postexercise. EI during the ad libitum breakfast in the morning postexercise tended to be lower in SM+OI (p = 0.087, d = 0.31). Gastrointestinal impacts of OI were apparent with increased ratings of flatulence (p = 0.026, d = 0.57) in participants the morning after the exercise session. Overall, the ingestion of a single dose of OI after an exercise session appears to induce subtle reductions in appetite, although the impact of these changes on acute and prolonged EI remains unclear.

Lifestyle-Based Obesity Care

Lifestyle intervention is an alluring concept. Changing behaviors to reduce food intake and increase energy expenditure will reduce body weight and body fat. Large randomized clinical trials in academic settings demonstrate lifestyle intervention can produce weight loss and significant health benefits. However, they also demonstrate the problems-not all participants are able to lose even 5%, and weight regain is common. Studies conducted in real-world settings achieve modest weight loss, but no reimbursement model supports it. Health care providers need to understand the benefits and limitations of lifestyle intervention delivery in the medical office setting.

Our biology working against us in obesity: A narrative review on implications for management of osteoarthritis

Obesity is the major modifiable risk factor for osteoarthritis (OA). A major focus of management in OA is weight loss. Although we live in an obesogenic environment, obesity has a predominantly genetic and epigenetic basis. This explains a person's weight set point which is defended by biological mechanisms making weight loss difficult to achieve and maintain long term, regardless of the methods used. Significant weight regain occurs after weight loss, with weight tending to return to pre-treatment levels after cessation of interventions including the glucagon-like peptide-1 (GLP-1) agonists. An area that has received little attention is the slow, insidious weight creep of 0.5-1 kg/year over adulthood that sees individuals relentlessly increase weight. There is evidence that low intensity, personalised lifestyle interventions can prevent this weight creep, providing patients with achievable goals. In this narrative review, we examine the evidence for weight loss in OA, the biological mechanisms that make weight loss difficult to achieve and maintain and the potential negative impacts on patients. We review the evidence for preventing weight gain, the improvement in patient outcomes and the potential for significant healthcare savings through reduced knee replacements. We propose a combined approach of weight loss when indicated, together with targeting weight creep across adult years and the potential role of metformin. Implementing these combined approaches is likely to be more effective in improving patient related outcomes, reducing joint damage and healthcare costs, than our current focus on achieving weight loss in OA.

Are motivational and self-regulation factors associated with 12 months' weight regain prevention in the NoHoW study? An analysis of European adults

PURPOSE

Preventing weight regain can only be achieved by sustained changes in energy balance-related behaviors that are associated with weight, such as diet and physical activity. Changes in motivation and self-regulatory skills can support long-term behavioral changes in the context of weight loss maintenance. We propose that experiencing a supportive climate care is associated with enhanced satisfaction of basic psychological needs, intrinsic goals, and autonomous motivation. These factors are expected to be associate with the utilization of self-regulation skills, leading to more sustained behavior changes and ultimately preventing weight regain. This hypothesis was tested in this ancillary analysis of the NoHoW trial, where the study arms were pooled and followed for 12 months.

METHODS

The NoHoW was a three-center, large-scale weight regain prevention full factorial trial. In this longitudinal study, data were collected in adults who lost > 5% weight in the past year (N = 870, complete data only, 68.7% female, 44.10 ± 11.86 years, 84.47 ± 17.03 kg) during their participation in a 12-month digital behavior change intervention. Weight and validated measures of motivational- and self-regulatory skills-related variables were collected at baseline, six- and 12 months. Change variables were used in Mplus' path analytical models informed by NoHoW's logic model.

RESULTS

The bivariate correlations confirmed key mediators' potential effect on weight outcomes in the expected causal direction. The primary analysis showed that a quarter of the variance (r2 = 23.5%) of weight regain prevention was achieved via the mechanisms of action predicted in the logic model. Specifically, our results show that supportive climate care is associated with needs satisfaction and intrinsic goal content leading to better weight regain prevention via improvements in self-regulatory skills and exercise-controlled motivation. The secondary analysis showed that more mechanisms of action are significant in participants who regained or maintained their weight.

CONCLUSIONS

These results contribute to a better understanding of the mechanisms of action leading to behavior change in weight regain prevention. The most successful participants used only a few intrinsic motivation-related mechanisms of action, suggesting that habits may have been learned. While developing a digital behavior change intervention, researchers and practitioners should consider creating supportive climate care to improve needs satisfaction and intrinsic goal contents.

TRIAL REGISTRATION

ISRCTN, ISRCTN88405328 , registered 12/22/2016.

Is dieting a risk for higher weight gain in normal-weight individual? A systematic review and meta-analysis

While there is an increasing prevalence of dieting in the overall population, weight loss (WL) practices could be a risk factor for weight gain (WG) in normal-weight (NW) individuals. The aim of the present work was to systematically review all the studies implicating diet restriction and body weight (BW) evolution in NW people. The literature search was registered in PROSPERO (CRD42021281442) and was performed in three databases from April 2021 to June 2022 for articles involving healthy NW adults. From a total of 1487 records initially identified, eighteen were selected in the systematic review. Of the eight dieting interventional studies, only one found a higher BW after weight recovery, but 75 % of them highlighted metabolic adaptations in response to WL favouring weight regain and persisting during/after BW recovery. Eight of the ten observational studies showed a relationship between dieting and major later WG, while the meta-analysis of observational studies results indicated that 'dieters' have a higher BW than 'non-dieters'. However, considering the high methodological heterogeneity and the publication bias of the studies, this result should be taken with caution. Moreover, the term 'diet' was poorly described, and we observed a large heterogeneity of the methods used to assess dieting status. Present results suggest that dieting could be a major risk factor for WG in the long term in NW individuals. There is, however, a real need for prospective randomised controlled studies, specifically assessing the relationship between WL induced by diet and subsequent weight in this population.

Obesity-related complications, healthcare resource use and weight loss strategies in six European countries: the RESOURCE survey

BACKGROUND

Obesity-related complications (ORCs), such as type 2 diabetes (T2D) and cardiovascular disease, contribute considerably to the clinical and economic impacts of obesity. To obtain a holistic overview of health and weight management attempts for people with obesity in Europe, we designed the cross-sectional RESOURCE survey to collect data on comorbidities, healthcare resource use (HCRU) and weight loss strategies from people with obesity in France, Germany, Italy, Spain, Sweden and the UK.

METHODS

Adults (≥18 years old) with self-reported body mass index (BMI) ≥30 kg/m2 who reported interacting with primary or secondary healthcare services in the past 12 months, but had not been pregnant during this time, were recruited from an existing consumer research panel. All data were self-reported via an online survey (May-June 2021). Weight changes over the past year were calculated from participants' estimated weights.

RESULTS

Of the 1850 participants in the survey, 26.3% reported that they had ≥3 ORCs from a set of 15 conditions of interest. The most frequently reported ORCs were hypertension (39.3% of participants), dyslipidaemia (22.8%) and T2D (17.5%). Participants in obesity class III (BMI 40 to <70 kg/m2) were more likely to report multiple ORCs than those in lower obesity classes. The presence of multiple ORCs was linked to various types of HCRU, including a significantly increased chance of reporting hospitalization in the past year. Most participants (78.6%) had attempted to lose weight in the past year, but of those who also reported estimated weight changes, 73.4% had not experienced clinically meaningful weight loss of ≥5%.

CONCLUSIONS

ORCs are common in people with obesity, and are linked to increased HCRU. Together with the low reported success rate of weight loss attempts, this highlights an unmet need in Europe for enhanced weight management support for people with obesity.

Factors that predict weight loss success differ by diet intervention type

Background

Many types of diet intervention can achieve negative energy balance and successful weight loss in persons with obesity. However, within any dietary strategy, there is large inter-individual variation in the weight loss response. The aim of this study is to determine factors that predict weight loss success for diet interventions that vary by macronutrient and caloric composition.

Methods

Participants with BMI 30.0 to 49.9 kg/m2 self-selected one of three diet intervention trials for weight loss: low carbohydrate (LOW CHO), low fat (LOW FAT), or low calorie (LOW KCAL). Multivariable regression models were developed to determine the significance of predictor demographic, body composition, metabolic, clinical, and dietary variables for each diet type.

Results

Weight loss over 12-16 weeks averaging -5.1 ± 4.0 kg from baseline weight, p < 0.001, was not significantly different among diet types. Several different factors were identified that account for the inter-individual variance in weight loss success. Regardless of diet type, the most robust predictor of weight loss success was completion of the intervention, accounting for 20-30% of the variance. Factors predicting diet intervention completion were age, physical activity level, blood leptin level, blood pressure, and the amount of weight loss occurring. Differences by diet type in cardiometabolic risk factor reduction were identified with LOW CHO decreasing glycemia/insulinemia factors, LOW FAT decreasing lipidemia factors, and LOW KCAL decreasing inflammatory factors.

Conclusion

These data provide evidence to inform more precise and personalized approaches to diet intervention for weight loss and cardiometabolic health.

An examination of individual, relational, and cultural risk for disordered eating in Asian American college students

Objective: This study examined how individual (satisfaction of basic psychological needs), relational (perceived achievement- and dependency-oriented parental psychological control), and cultural (ethnic identity) factors may contribute to Asian American college students' (18 - 25 years of age) disordered eating. Participants: Asian American college students (N = 118) participated in the study. Methods: Participants completed a cross-sectional survey study. Moderated mediation models were used to analyze the data. Results: Analyses showed that perceived achievement-oriented, but not dependency-oriented, parental psychological control was more strongly associated with psychological needs satisfaction at higher, compared to lower, levels of ethnic identity. Conclusions: Findings highlighted the importance of both parenting and ethnic identity among Asian American college students' psychological needs and risk for disordered eating. The complex relations among achievement expectations, ethnic identity and wellbeing in Asian Americans are discussed. The results can inform intervention and prevention programs attending to the needs of this population.

Age and gender differences in misperceptions of body shape in a Taiwanese population

OBJECTIVES

Most studies of body size perception have been performed in adolescents, and most focus on gender differences in accurate perception of body size. This study investigated misperceptions of body sizes among males and females at different stages of adulthood in Taiwan.

DESIGNS

In-person home interviews were used to proportionally and randomly select 2095 adult men and women to answer the East Asian Social Survey. Participants were divided into 18-39, 40-64, and 65 + age groups. The main variables analyzed were self-perceived body size and standardized BMI.

RESULTS

Women, unlike men, were more likely to misperceive their body size as being overweight (OR = 2.92; p < .001). People with higher self-perceived social status were less likely to misperceive themselves as overweight (OR = 0.91; p = .01). People with college educations were 2.35 times more likely to overestimate their body size as being heavier than they were (p < .001) and less likely to underestimate it as being thinner than they were (OR = 0.45; p < .001). Women 18-35 and 36-64 years old were 6.96 and 4.31 times more likely (p < .001) to misperceive themselves as being overweight than women 65 or older, who were more likely to misperceive themselves as being too thin. There were no significant differences in body size misperceptions among the three age groups of adult men (p > .05). We found no different significant discrepancies between self-perceived body size and actual BMI between the older men and women (p = .16). However, younger and middle-aged men were 6.67 and 3.1 times more likely to misperceive themselves as being too thin than women in their same age groups (OR = 0.15 and OR = 0.32, respectively).

CONCLUSIONS

Age and gender affect self-perceptions of body size in Taiwan. Overall, women are more likely than men to misperceive themselves as being too big, and men are more likely than women to misperceive themselves as too thin. Older women, however, were more likely to misperceive themselves as being too thin. Clinicians and health educators should know that people's perceptions and concerns regarding their body size vary by age and gender.

The impact of the first COVID-19 lockdown on weight management practices in UK adults: A self-regulation perspective

This study aimed to identify the impact of the first UK COVID-19 lockdown on individuals' weight management attempts (WMA). A self-regulation theoretical framework was used to identify predictors of continuing with a WMA, and weight change during the lockdown. An online retrospective cross-sectional study was conducted after the first UK COVID-19 lockdown. The sample consisted of 166 UK adults (M:31.08, SD:12.15) that were trying to manage their weight before the lockdown started. The survey assessed changes in WMA and practices, and measured perceived stress, flexible/rigid restraint, uncontrolled eating, craving control, and self-compassion. Results showed that 56% of participants reported disruption to their WMA during the lockdown. Participants with lower levels of perceived stress and higher flexible restraint were more likely to continue their WMA. Flexible restraint was a significant predictor of weight change. Interventions that promote flexibility in weight management may be beneficial for at-risk individuals under lockdown conditions.

A qualitative study of ecological and motivational factors to inform weight management interventions for Black men in the rural South of the United States

RATIONALE AND OBJECTIVE

Black men in the rural South of the United States (US) are underrepresented in weight management behavioral trials. Qualitative research is needed to inform interventions that can reduce obesity and health disparities in this population. We explored how intrapersonal, social, and environmental factors affect motivation and weight-related behaviors and how to culturally adapt behavioral interventions for Black men in the rural South.

METHODS

We conducted individual telephone interviews with 23 Black men (mean age 50 ± 14 years) with overweight or obesity living in rural South Carolina communities in 2020 and 2021. Interviews were audio recorded, professionally transcribed, and coded by two men's health researchers who achieved an intercoder reliability of 70%. Content analysis using QSR NVivo 12 was used to generate themes using deductive and inductive approaches.

RESULTS

Physical health and health behaviors were perceived as key determinants of overall health. Family, friends, and other social contacts often provided positive social support that increased motivation but also hindered motivation by engaging in behaviors men were trying to avoid. Younger participants had stronger views of rural environments not supporting healthy lifestyles, which compounded personal challenges such as time constraints and lack of motivation. Comfort was discussed as a critical program consideration, and gender concordance among program participants and facilitators was perceived as promoting comfort. Participants noted preferences and benefits of in-person, group programs emphasizing physical activity, and younger participants more strongly endorsed programs that incorporated sports and competition.

CONCLUSIONS

Findings from this study provide important evidence to inform the development of weight management interventions for Black men in the rural US South. Based on these findings, an innovative, competitive "football-themed" weight management program promoting peer support and integrating competitive physical activities is being evaluated for younger Black men in the rural South.

Theory to treatment to theory: Evolving a community-based obesity intervention

Within weight-loss treatments, a better understanding of psychosocial correlates of exercise and controlled eating is required to improve lagging outcomes. Within this two-phase study, women with obesity participating in community-based treatments with educational (Phase 1 n = 57, Phase 2 n = 44) and behavioral (Phase 1 n = 80, Phase 2 n = 53) formats were contrasted on psychosocial variables over 3 and 6 months and their interrelations based on the mood-behavior-model and coaction theory. Phase 1 findings informed curricular extensions in Phase 2. In Phase 1, there were significant overall improvements in total mood disturbance, self-regulation of exercise, self-regulation of eating, and weight, which were more pronounced in the behavioral vs. educational format group (-3.5 % vs. -1.4 % weight loss, respectively). Mediation analyses indicated that change in self-regulation of exercise mediated the prediction of change in self-regulation of eating by mood change. Phase 2 findings were similar; however, effect sizes were greater (-6.2 % vs. -2.9 % weight loss, respectively). Within both phases, increased self-regulation of eating significantly predicted weight reduction. Paths from changes in mood→self-regulation of exercise→self-regulation of eating suggested future program attention focus on treatment-associated mood change reinforcing self-regulation, and self-regulation generalizing from an exercise to eating context. Methods of progressing treatment curricula via theory-testing were suggested.

Low eating self-efficacy is associated with unfavorable eating behavior tendencies among individuals with overweight and obesity

Success in long-term weight management depends partly on psychological and behavioral aspects. Understanding the links between psychological factors and eating behavior tendencies is needed to develop more effective weight management methods. This population-based cross-sectional study examined whether eating self-efficacy (ESE) is associated with cognitive restraint (CR), uncontrolled eating (UE), emotional eating (EE), and binge eating (BE). The hypothesis was that individuals with low ESE have more unfavorable eating behavior tendencies than individuals with high ESE. Participants were classified as low ESE and high ESE by the Weight-Related Self-Efficacy questionnaire (WEL) median cut-off point. Eating behavior tendencies were assessed with Three Factor Eating Questionnaire R-18 and Binge Eating Scale, and additionally, by the number of difficulties in weight management. The difficulties were low CR, high UE, high EE, and moderate or severe BE. Five hundred and thirty-two volunteers with overweight and obesity were included in the study. Participants with low ESE had lower CR (p < 0.03) and higher UE, EE, and BE (p < 0.001) than participants with high ESE. Thirty-nine percent of men with low ESE had at least two difficulties in successful weight control while this percentage was only 8% in men with high ESE. In women, the corresponding figures were 56% and 10%. The risk of low ESE was increased by high UE [OR 5.37 (95% CI 1.99-14.51)], high EE [OR 6.05 (95% CI 2.07-17.66)], or moderate or severe BE [OR 12.31 (95% CI 1.52-99.84)] in men, and by low CR [OR 5.19 (95% CI 2.22-12.18)], high UE [OR 7.20 (95% CI 2.41-19.22)], or high EE [OR 23.66 (95% CI 4.79-116.77)] in women. Low ESE was associated with unfavorable eating behavior tendencies and multiple concomitant difficulties in successful weight loss promotion. These eating behavior tendencies should be considered when counseling patients with overweight and obesity.

Prospective study of weight loss and all-cause-, cardiovascular-, and cancer mortality

Effects of repeated weight changes on mortality are not well established. In this prospective cohort study, we followed 34,346 individuals from 1997 to 2018 for all-cause mortality, and 2016 for cause-specific mortality. At baseline, participants self-reported amount and frequency of prior weight loss. During 20.6 (median) years of follow-up, we identified 5627 deaths; 1783 due to cancer and 1596 due to cardiovascular disease (CVD). We used Cox Proportional Hazards models to estimate multivariable-adjusted Hazard Ratios (HRs) and 95% confidence intervals (CI). Participants with a weight loss > 10 kg had higher rates of all-cause (HR 1.22; 95%CI 1.09-1.36) and CVD mortality (HR 1.27; 95%CI 1.01-1.59) compared to individuals with no weight loss. Men who had lost > 10 kg had higher all-cause (HR 1.55; 95%CI 1.31-1.84) and CVD mortality (HR 1.55; 95%CI 1.11-2.15) compared to men with no weight loss. Participants who had lost ≥ 5 kg three times or more prior to baseline had increased rates of all-cause (HR 1.16; 95%CI 1.03-1.30) and CVD mortality (HR 1.49; 95%CI 1.20-1.85) compared to participants with no weight loss. We found no association between weight loss and cancer mortality. We conclude that previous and repeated weight loss may increase all-cause and CVD mortality, especially in men.

Polycystic ovary syndrome is associated with weight-loss attempts and perception of overweight independent of BMI: a population-based cohort study

OBJECTIVE

Up to 70% of women with polycystic ovary syndrome (PCOS) have pre-obesity or obesity. The aim of this study was to investigate whether women with PCOS have more weight-loss attempts than women without PCOS, regardless of BMI. Moreover, women's weight perceptions in relation to previous weight-loss attempts were evaluated.

METHODS

A population-based birth cohort study included women with (n = 278) and without PCOS (control individuals, n = 1560) who were examined at ages 31 and 46 years with questionnaires and clinical examinations.

RESULTS

Women with PCOS had more weight-loss attempts compared with control individuals at age 31 (47% vs. 34%, p < 0.001) and 46 years (63% vs. 47%, p < 0.001). At age 46 years, PCOS was associated with multiple weight-loss attempts in the adjusted model (odds ratio: 1.43 [95% CI: 1.00-2.03], p = 0.05). The perception of having overweight was more prevalent in those with PCOS, even among participants with normal weight, at age 31 (PCOS 47% vs. control 34%, p = 0.014) and 46 years (PCOS 60% vs. control 39%, p = 0.001).

CONCLUSIONS

Women with PCOS were more likely to have experienced multiple weight-loss attempts and a perception of having overweight compared with control individuals, regardless of obesity status.

Computational mechanisms underpinning greater exploratory behaviour in excess weight relative to healthy weight adolescents

Obesity in adolescence is associated with cognitive changes that lead to difficulties in shifting unhealthy habits in favour of alternative healthy behaviours, similar to addictive behaviours. An outstanding question is whether this shift in goal-directed behaviour is driven by over-exploitation or over-exploration of rewarding outcomes. Here, we addressed this question by comparing explore/exploit behaviour on the Iowa Gambling Task in 43 adolescents with excess weight against 38 adolescents with healthy weight. We computationally modelled both exploitation behaviour (e.g., reinforcement sensitivity and inverse decay parameters), and explorative behaviour (e.g., maximum directed exploration value). We found that overall, adolescents with excess weight displayed more behavioural exploration than their healthy-weight counterparts - specifically, demonstrating greater overall switching behaviour. Computational models revealed that this behaviour was driven by a higher maximum directed exploration value in the excess-weight group (U = 520.00, p = .005, BF₁₀ = 5.11). Importantly, however, we found substantial evidence that groups did not differ in reinforcement sensitivity (U = 867.00, p = .641, BF₁₀ = 0.30). Overall, our study demonstrates a preference for exploratory behaviour in adolescents with excess weight, independent of sensitivity to reward. This pattern could potentially underpin an intrinsic desire to explore energy-dense unhealthy foods - an as-yet untapped mechanism that could be targeted in future treatments of obesity in adolescents.

Weight-Control Behaviors and Dietary Intake in Chinese Adults: An Analysis of Three National Surveys (2002–2015)

Weight control through dietary management is becoming increasingly common worldwide. This study aimed to evaluate and compare the dietary intake and diet quality between Chinese adults with and without weight-control behaviors. Data were collected from the China National Nutrition Survey 2002, 2012, and 2015. Dietary intake was assessed using a combination of 24 h dietary recall of three consecutive days and a weighing method. Diet quality was calculated based on China healthy diet index (CHDI). A total of 167,355 subjects were included, of which 11,906 (8.0%) adults reported attempting to control weight within the past 12 months. Participants with weight control had lower daily total energy intake, as well as lower percentages of energy from carbohydrates, low-quality carbohydrates, and plant protein, but higher percentages of energy from protein, fat, high-quality carbohydrates, animal protein, saturated fatty acids, and monounsaturated fatty acids than those without weight control. Additionally, the CHDI score in the weight-control group was higher than those without (53.40 vs. 48.79, p < 0.001). Fewer than 40% of participants in both groups met the requirement for all specific food groups. Chinese adults who reported weight-control behaviors had an energy-restricted diet characterized by reduced carbohydrate intake and overall higher diet quality compared with those without dietary-control behaviors. However, both groups had significant room for improvement in meeting dietary recommendations.

Weight cycling based on altered immune microenvironment as a result of metaflammation

As a result of the obesity epidemic, more people are concerned about losing weight; however, weight regain is common, leading to repeated weight loss and weight cycling. The health benefits of early weight loss are nullified by weight regain after weight cycling, which has much more severe metabolic consequences. Weight cycling alters body composition, resulting in faster fat recovery and slower muscle reconstruction. This evident fat accumulation, muscle loss, and ectopic fat deposition destroy the intestinal barrier, increase the permeability of the small intestinal epithelium, and cause the lipotoxicity of lipid metabolites and toxins to leak into extraintestinal tissues and circulation. It causes oxidative stress and hypoxia in local tissues and immune cell infiltration in various tissues, all contributing to the adaptation to this metabolic change. Immune cells transmit inflammatory responses in adipose and skeletal muscle tissue by secreting cytokines and adipokines, which mediate immune cell pathways and cause metaflammation and inefficient metabolic degradation. In this review, we focus on the regulatory function of the immunological microenvironment in the final metabolic outcome, with a particular emphasis on the cellular and molecular processes of local and systemic metaflammation induced by weight cycling-induced changes in body composition. Metaflammation in adipose and muscle tissues that is difficult to relieve may cause weight cycling. As this chronic low-grade inflammation spreads throughout the body, metabolic complications associated with weight cycling are triggered. Inhibiting the onset and progression of metabolic inflammation and enhancing the immune microenvironment of adipose and muscle tissues may be the first step in addressing weight cycling.

Weight management strategies in Middle-Aged Women (MAW): Development and validation of a questionnaire based on the Oxford Food and Activity Behaviors Taxonomy (OxFAB-MAW) in a Portuguese sample

Background

The Oxford Food and Activity Behaviors (OxFAB) taxonomy systematize the cognitive-behavioral strategies adopted by individuals who are attempting to manage their weight. The present study aimed to (1) develop a questionnaire based on the OxFAB taxonomy, specifically adapted for middle-aged women-the OxFAB-MAW-stage of life and sex, which present a high incidence of obesity, (2) assess the psychometric properties of this tool, and (3) evaluate the discriminative power of the OxFAB-MAW (normal weight vs. obesity).

Methods

Overall, 1,367 Portuguese middle-aged women between 45 and 65 years (M = 52.3, SD = 5.15) filled in a sociodemographic, health, and menopause-related questionnaire, as well as the OxFAB-MAW.

Results

Confirmatory factor analysis demonstrated an acceptable model fit (comparative fit index = 0.928, Tucker-Lewis index = 0.913, root mean square error of approximation = 0.072, and standardized root mean square residual = 0.054). Five domains with one item were grouped into other domains, and the Weight Management Aids domain was also removed. The OxFAB-MAW showed factorial, convergent, discriminant, and external validity, as well as composite reliability.

Conclusion

The OxFAB-MAW questionnaire is a valid, reliable, and theory-driven tool for assessing weight management strategies in middle-aged women, being able to discriminate between clinical and non-clinical groups (normal weight vs. obesity) in several domains. This instrument can be used to gather valid and reliable data, useful in both research and clinical settings (especially focused on structuring interventions and preventive obesity programs within this specific life cycle stage).

Compensatory eating after exercise in everyday life: Insights from daily diary studies

There is considerable variability in how successful people are in losing weight via exercise programs. Experimental research suggests that greater food intake after exercise may be one factor underlying this variability, but no studies have assessed patterns of post-exercise eating behaviour over time in naturalistic settings. Thus, we aimed to assess how exercise and contextual factors (e.g., hunger, presence of others) influence the healthiness and amount of food eaten after exercise in two daily diary studies. In Study 1, participants (n = 48) reported their food intake and exercise daily for 28 days. For each meal, they provided a brief description of the food(s) eaten which were then categorised as healthy, unhealthy, or mixed (neither healthy nor unhealthy) by two independent coders. Study 2 used the same method, but participants (n = 55) also reported the portion size of each meal. Hierarchical linear modelling showed that in Study 1, contrary to expectations, post-exercise meals were less likely to be unhealthy (relative to mixed) than were random meals from non-exercise days (OR = 0.63, p = .011), and that participants ate proportionally fewer unhealthy meals on exercise days compared to non-exercise days (b = -4.27, p = .004). Study 2 replicated these findings, and also found that participants consumed larger meals after exercise in comparison to random meals from non-exercise days (b = 0.25, p < .001). Participants were not consistently engaging in compensatory eating by eating less healthily after exercise compared to on non-exercise days, but they did eat larger portions post-exercise. This work highlights the need for naturalistic methods of assessing compensatory eating, and has the potential to facilitate development of strategies to improve health behaviour regulation.

A Large-Scale Observational Analysis of Social Media Data Reveals Major Public Misperception of the Attainability of Drastic Weight Loss by Dieting

INTRODUCTION

Diet forums in social media websites provide an opportunity to glimpse the experience of different weight loss diet strategies reported by tens of thousands of individuals.

METHODS

We analyzed all postings with weight information from the six major Reddit weight loss diet forums ("subreddits") as reported by forum participants.

RESULTS

Data were collected from January 2011 to April 2020 from all 55,900 users posting weight information. Average start BMI was in the overweight or obese range (26-34 kg/m2), and average goal BMI was in the normal range (21.5-24.5 kg/m2) for all subreddits. There is correlation between start BMI and goal BMI (R2 = 0.63, p < 10-10) and between planned weight loss and reported weight loss (R2 = 0.56, p < 10-10). Approximately 80% of forum participants reported a weight loss that was greater than 5% of their initial body weight. Actual reported weight loss was less than half of goal weight loss. Average reported weight loss and adherence were highest in the keto and loseit subreddits. More upvotes and fewer downvotes were associated with higher reported weight loss in five of the six subreddits.

CONCLUSIONS

Despite the need for cautious interpretation of these data due to self-selection of users who updated weight loss and the possibility of unreliable weight reports, the study has several findings. Average goal BMI was in the normal weight range, demonstrating a highly unrealistic perception, in a very large lay-public cohort, of the plausibility of losing all excess weight. The success in weight loss and maintenance in self-selected individuals who continued reporting weight for many months may demonstrate the subjective value some individuals can obtain from forum participation.

Altered motivation states for physical activity and 'appetite' for movement as compensatory mechanisms limiting the efficacy of exercise training for weight loss

Weight loss is a major motive for engaging in exercise, despite substantial evidence that exercise training results in compensatory responses that inhibit significant weight loss. According to the Laws of Thermodynamics and the CICO (Calories in, Calories out) model, increased exercise-induced energy expenditure (EE), in the absence of any compensatory increase in energy intake, should result in an energy deficit leading to reductions of body mass. However, the expected negative energy balance is met with both volitional and non-volitional (metabolic and behavioral) compensatory responses. A commonly reported compensatory response to exercise is increased food intake (i.e., Calories in) due to increased hunger, increased desire for certain foods, and/or changes in health beliefs. On the other side of the CICO model, exercise training can instigate compensatory reductions in EE that resist the maintenance of an energy deficit. This may be due to decreases in non-exercise activity thermogenesis (NEAT), increases in sedentary behavior, or alterations in sleep. Related to this EE compensation, the motivational states associated with the desire to be active tend to be overlooked when considering compensatory changes in non-exercise activity. For example, exercise-induced alterations in the wanting of physical activity could be a mechanism promoting compensatory reductions in EE. Thus, one's desires, urges or cravings for movement-also known as "motivation states" or "appetence for activity"-are thought to be proximal instigators of movement. Motivation states for activity may be influenced by genetic, metabolic, and psychological drives for activity (and inactivity), and such states are susceptible to fatigue-or reward-induced responses, which may account for reductions in NEAT in response to exercise training. Further, although the current data are limited, recent investigations have demonstrated that motivation states for physical activity are dampened by exercise and increase after periods of sedentarism. Collectively, this evidence points to additional compensatory mechanisms, associated with motivational states, by which impositions in exercise-induced changes in energy balance may be met with resistance, thus resulting in attenuated weight loss.

Do eating behavior traits predict energy intake and body mass index? A systematic review and meta-analysis

At present, it is unclear whether eating behavior traits (EBT) predict objectively measured short-term energy intake (EI) and longer-term energy balance as estimated by body mass index (BMI). This systematic review examined the impact of EBT on BMI and laboratory-based measures of EI in adults ( ≥ 18 years) in any BMI category, excluding self-report measures of EI. Articles were searched up until 28th October 2021 using MEDLINE, PsycINFO, EMBASE and Web of Science. Sixteen EBT were identified and the association between 10 EBT, EI and BMI were assessed using a random-effects meta-analysis. Other EBT outcomes were synthesized qualitatively. Risk of bias was assessed with the mixed methods appraisal tool. A total of 83 studies were included (mean BMI = 25.20 kg/m² , mean age = 27 years and mean sample size = 70). Study quality was rated moderately high overall, with some concerns in sampling strategy and statistical analyses. Susceptibility to hunger (n = 6) and binge eating (n = 7) were the strongest predictors of EI. Disinhibition (n = 8) was the strongest predictor of BMI. Overall, EBT may be useful as phenotypic markers of susceptibility to overconsume or develop obesity (PROSPERO: CRD42021288694).

Weight fluctuation, mortality, and cardiovascular disease in adults in 18 years of follow-up: Tehran Lipid and Glucose Study

PURPOSE

Controversies exist in the effect of body weight loss and fluctuation on cardiovascular disease (CVD) and mortality. This study aims to assess the effect of weight variability on CVD and all-cause and cardiovascular mortality in the Tehran Lipid and Glucose Study (TLGS) cohort.

METHOD

Participants aged  ≥ 40 year at the baseline period with at least 3 BMI measurements were included in this study. After excluding individuals with cancer, CVD, end-stage renal disease, systemic use of glucocorticoids, pregnancy, and missing covariates at the baseline, a total of 3461 participants were enrolled and followed for 18 years. BMI variability was defined using root mean squared error (RMSE) and average successive variability (ASV). In the RMSE method, BMI variability was calculated using the best-fitting model for BMI trend of each subject. Multivariate Cox proportional hazard models were applied to assess BMI variability's effect on CVD and mortality.

RESULTS

Among the 3461 participants in this study, the group with the highest weight variability had an increased risk of death for all-cause (HR 1.65; 95% CI 1.21-2.25), non-cardiovascular (HR 1.77; 95% CI 1.24-2.53), and non-cancer (HR 1.77; 95% CI 1.25-2.50) mortality. However, BMI variability showed to be protective against CVD (HR 0.76; 95% CI 0.6-0.97). These findings were significant in males, non-smokers, participants with age  ≤ 60 year, BMI < 30, negative BMI slope, and both diabetic and non-diabetic subjects.

CONCLUSION

High BMI variability is associated with increased risk of all-cause, non-CVD, and non-cancer mortality, although protective for the CVD event. Appropriate strategies for body weight maintenance after weight loss could be adopted to avoid weight variability, particularly in non-obese subjects.

Peer Appearance Teasing and Restrained Eating Among Chinese Adolescent Girls: A Mediation Model of Fear of Negative Appearance Evaluation and Body Surveillance

Restrained eating is becoming widespread recently. The present study aimed to examine whether peer appearance teasing was positively associated with restrained eating among Chinese adolescent girls and whether this association was mediated by fear of negative appearance evaluation (FNAE) and body surveillance. A sample of 720 Chinese adolescent girls completed questionnaires on peer appearance teasing, FNAE, body surveillance, and restrained eating. Peer appearance teasing was significantly and positively related to girls' restrained eating. FNAE mediated the relationship between peer appearance teasing and restrained eating. Furthermore, the association between peer appearance teasing and restrained eating was sequentially mediated by FNAE and body surveillance. The findings of this study provide new insights into the development of restrained eating among adolescent girls, and highlight peer appearance teasing and body surveillance as potential targets for intervention programs regarding body image concerns and eating disorders.

Obesity prevention and related public health advertising versus competing commercial advertising expenditure in Australia

Mass media campaigns can change attitudes and behaviours to improve population health. However, a key challenge is achieving share of voice in a complex and cluttered media environment. The aim of this study was to compare advertising expenditure on public health campaigns for obesity prevention (and related healthy eating and physical activity campaigns) with competing commercial categories of (a) sugary drinks, (b) artificially sweetened drinks and (c) diet/weight loss products and programmes. These commercial products may either undermine or dilute public health messages by directly contributing to poor health or confusing the public about the best ways to sustain a healthy lifestyle. Monthly estimates of advertising expenditure in Australian media (television, outdoor, cinema, radio, newspapers, magazines and digital) were obtained from Nielsen Media for 2016–18. Eligible public health advertising expenditure for the entire period (total AUD$27M) was vastly outweighed by the commercial categories of sugary drinks (AUD$129M) and diet/weight loss products and services (AUD$122M). Artificially sweetened drinks accounted for an additional AUD$23M of expenditure. These results highlight the need to rebalance the ratio of advertising to support public health in Australia through increased funding for obesity prevention and related campaigns, and critically, through government regulation to limit competing commercial advertising.

High-protein diet prevents fat mass increase after dieting by counteracting Lactobacillus-enhanced lipid absorption

Dietary restriction is widely used to reduce fat mass and lose weight in individuals with or without obesity; however, weight regain after dieting is still a big challenge, and the underlying mechanisms remain largely elusive. Here we show that refeeding after various types of dieting induces quick fat accumulation in mice and enhanced intestinal lipid absorption contributes to post-dieting fat mass increase. Moreover, refeeding after short-term dietary restriction is accompanied by an increase in intestinal Lactobacillus and its metabolites, which contributes to enhanced intestinal lipid absorption and post-dieting fat mass increase; however, refeeding a high-protein diet after short-term dietary restriction attenuates intestinal lipid absorption and represses fat accumulation by preventing Lactobacillus growth. Our results provide insight into the mechanisms underlying fat mass increase after dieting. We also propose that targeting intestinal Lactobacillus to inhibit intestinal lipid absorption via high-protein diet or antibiotics is likely an effective strategy to prevent obesity after dieting.

Physiology of the Weight-Reduced State and Its Impact on Weight Regain

Obesity is a chronic disease characterized by long duration, slow progression, and periods of remission and relapses. Despite the development of effective medical and surgical interventions and millions of people conducting tremendous personal efforts to manage their weight every year, recidivism remains a significant barrier to attaining long-term weight maintenance. This review aimed to explain the underlying physiology of the weight-reduced state including changes in energy balance, adipose tissue, genetic, environmental, and behavioral factors that may predispose individuals to weight regain following weight loss.

The impact of living through COVID-19 pandemic on mental health, food insecurity, loneliness and health behaviours in people with obesity

BACKGROUND

The COVID-19 pandemic has negatively impacted people living with obesity. The aim was to examine the continued impact of the COVID-19 pandemic on the mental health of people living with obesity and associations with food insecurity, loneliness and health-related behaviours.

METHODS

The study recruited 1187 UK adults living with obesity who completed an online survey, which examined mental health and associations with food insecurity, loneliness and health-related behaviours from July 2020 (end of the first lockdown in the United Kingdom) to the point they completed the survey in 2021. Regression analyses were used to examine relationships between outcome variables and demographic factors, and hierarchical linear regression models were used to assess levels of loneliness, depression and well-being.

RESULTS

Participants reported worse loneliness, depression, well-being and food insecurity compared to pre-COVID. However, participants reported attempting to lose weight, healthier food shopping, diet and increased physical activity. Quality and quantity of sleep deteriorated compared to prior to COVID-19.

CONCLUSIONS

Adults living with obesity in the United Kingdom report a continued negative impact of the COVID-19 pandemic upon their mental health together with increased loneliness and food insecurity. However, our findings suggest that UK adults living with obesity have increased their engagement in positive health behaviours and were attempting to lose weight.

Motivational and self‐efficacy reciprocal effects during a 12‐month' weight regain prevention program

OBJECTIVE

Weight regain prevention is a critical public health challenge. Digital behaviour change interventions provide a scalable platform for applying and testing behaviour change theories in this challenging context. This study's goal was to analyse reciprocal effects between psychosocial variables (i.e., needs satisfaction, eating regulation, self-efficacy) and weight over 12 months using data from a large sample of participants engaged in a weight regain prevention trial.

METHODS

The NoHoW study is a three-centre, large-scale weight regain prevention trial. Adults who lost >5% of their weight in the past year (N = 1627, 68.7% female, 44.10 ± 11.86 years, 84.47 ± 17.03 kg) participated in a 12-month' digital behaviour change-based intervention. Weight and validated measures of basic psychological needs satisfaction, eating regulation and self-efficacy were collected at baseline, six- and 12 months. Correlational, latent growth models and cross-lagged analysis were used to identify potential reciprocal effects.

RESULTS

Baseline higher scores of needs satisfaction and self-efficacy were associated with six- and 12-month' weight loss. Baseline weight was linked to all psychosocial variables at six months, and six-months weight was associated with needs satisfaction and self-efficacy at 12 months. During the 12 months, increases in eating regulation, needs satisfaction and self-efficacy were associated with weight loss over the same period, and reciprocal effects were observed between the variables, suggesting the existence of Weight Management Cycles.

CONCLUSIONS

While further studies are needed, during long-term weight regain prevention, weight decrease, needs satisfaction and self-efficacy may lead to Weight Management Cycles, which, if recurrent, may provide sustained prevention of weight regain.

Food for thought: diet-induced impairments to decision-making and amelioration by N-acetylcysteine in male rats

RATIONALE

Attempts to lose weight often fail despite knowledge of the health risks associated with obesity and determined efforts. We previously showed that rodents fed an obesogenic diet displayed premature habitual behavioural control and weakened flexible decision-making based on the current value of outcomes produced by their behaviour. Thus, habitual control may contribute to failed attempts to modify eating behaviours.

OBJECTIVES

To examine the effects of an obesogenic diet on behavioural control and glutamate transmission in dorsal striatum regions and to assess the ability of N-acetylcysteine (NAC) to reverse deficits.

METHODS

Here, we examined diet-induced changes to decision-making and used in vitro electrophysiology to investigate the effects of diet on glutamate transmission within the dorsomedial (DMS) and dorsolateral (DLS) striatum, areas that control goal-directed and habitual behaviours, respectively. We administered NAC in order to normalize glutamate release and tested whether this would restore goal-directed performance following an obesogenic diet.

RESULTS

We found that an obesogenic diet reduced sensitivity to outcome devaluation and increased glutamate release in the DMS, but not DLS. Administration of NAC restored goal-directed control and normalized mEPSCs in the DMS. Finally, NAC administered directly to the DMS was sufficient to reinstate sensitivity to outcome devaluation following an obesogenic diet.

CONCLUSIONS

These data indicate that obesogenic diets alter neural activity in the basal ganglia circuit responsible for goal-directed learning and control which leads to premature habitual control. While the effects of diet are numerous and widespread, normalization of glutamatergic activity in this circuit is sufficient for restoring goal-directed behaviour.

Attitudes Toward Obesity, Willingness to Lose Weight, and Treatment Preferences Among Overweight and Obese Saudi Adults

Background: Obesity has become a major health concern worldwide and is associated with several diseases and complications. Losing weight is an effective strategy to improve body mass index and prevent the complications of obesity. However, weight loss is dependent on the attitude of individuals toward obesity as well as their willingness to lose weight.

Aim: To explore attitudes toward obesity, willingness to lose weight, and treatment preferences among overweight and obese Saudi adults.

Methods: An analytical cross-sectional study was conducted among overweight and obese Saudis. We targeted adults aged 18 years and older, who visited family medicine clinics at King Abdulaziz Medical City for the National Guard in Riyadh, Saudi Arabia. The study was conducted from December 2020 to June 2021 using a self-administered questionnaire.

Results: Of the 403 participants, 82.5% were dissatisfied with their current body weight. Controlling chronic disease was a major motive for improving body weight (53.2%), and exercise and diet were the most preferred strategies to lose body weight. Age was a determinant in the attitude and willingness of participants to lose weight (p = 0.0001).

Conclusion: Participants in the current study reported high dissatisfaction rates about current weight and willingness to improve body weight. This should encourage healthcare providers to initiate weight status discussions and management with their overweight and obese clients.

Can we have a second helping? A preregistered direct replication study on the neurobiological mechanisms underlying self-control

Self‐control is of vital importance for human wellbeing. Hare et al. (2009) were among the first to provide empirical evidence on the neural correlates of self‐control. This seminal study profoundly impacted theory and empirical work across multiple fields. To solidify the empirical evidence supporting self‐control theory, we conducted a preregistered replication of this work. Further, we tested the robustness of the findings across analytic strategies. Participants underwent functional magnetic resonance imaging while rating 50 food items on healthiness and tastiness and making choices about food consumption. We closely replicated the original analysis pipeline and supplemented it with additional exploratory analyses to follow‐up on unexpected findings and to test the sensitivity of results to key analytical choices. Our replication data provide support for the notion that decisions are associated with a value signal in ventromedial prefrontal cortex (vmPFC), which integrates relevant choice attributes to inform a final decision. We found that vmPFC activity was correlated with goal values regardless of the amount of self‐control and it correlated with both taste and health in self‐controllers but only taste in non‐self‐controllers. We did not find strong support for the hypothesized role of left dorsolateral prefrontal cortex (dlPFC) in self‐control. The absence of statistically significant group differences in dlPFC activity during successful self‐control in our sample contrasts with the notion that dlPFC involvement is required in order to effectively integrate longer‐term goals into subjective value judgments. Exploratory analyses highlight the sensitivity of results (in terms of effect size) to the analytical strategy, for instance, concerning the approach to region‐of‐interest analysis.

Weight loss strategies, weight change, and type 2 diabetes in US health professionals: A cohort study

BACKGROUND

Weight loss is crucial for disease prevention among individuals with overweight or obesity. This study aimed to examine associations of weight loss strategies (WLSs) with weight change and type 2 diabetes (T2D) risk among US health professionals.

METHODS AND FINDINGS

This study included 93,110 participants (24 to 60 years old; 11.6% male) from the Nurses' Health Study (NHS), NHSII, and Health Professionals Follow-Up Study (HPFS) cohorts who were free of T2D, cardiovascular disease, and cancer at baseline (1988 for NHS/HPFS and 1989 for NHSII) for analyses of weight change and 104,180 (24 to 78 years old; 14.2% male) for T2D risk assessment. WLSs used to achieve an intentional weight loss of 4.5+ kg were collected in 1992 (NHS/HPFS)/1993 (NHSII) and grouped into 7 mutually exclusive categories, including low-calorie diet, exercise, low-calorie diet and exercise, fasting, commercial weight loss program (CWLP), diet pills, and FCP (selected at least 2 methods from fasting, CWLP, and pill). The reference group was participants who did not attempt to lose weight. Generalized estimating equations and Cox regression were applied to estimate up to 10-year weight change trajectory and incident T2D risk through 2016 (NHS/HPFS)/2017 (NHSII), respectively. The associations of WLSs with weight change and T2D risk were differential by baseline body weight (Pinteraction < 0.01). Among individuals with obesity, all WLSs tended to associate with less weight gain [ranging from -4.2% (95% confidence interval (CI), -5.1% to -3.2%; P < 0.001) for exercise to -0.3% (-1.2% to 0.7%; P > 0.99) for FCP] and a lower T2D risk [hazard ratios (HRs) ranging from 0.79 (0.66 to 0.95; P = 0.04) for exercise to 0.87 (0.66 to 1.13; P = 0.30) for pill]. Such a pattern was less clear among overweight individuals: the difference of weight change varied from -2.5% (-3.0% to -2.1%; P < 0.001) for exercise to 2.0% (1.3% to 2.7%; P < 0.001) for FCP, and HRs of T2D varied from 0.91 (0.77 to 1.07; P = 0.29) for exercise to 1.42 (1.11 to 1.81; P = 0.02) for pill. The pattern was further inverted among lean individuals in that weight change ranged from -0.4% (-0.6% to -0.1%; P = 0.02) for exercise to 3.7% (3.1% to 4.3%; P < 0.001) for FCP, and the HRs of T2D ranged from 1.09 (0.91 to 1.30; P = 0.33) for exercise to 1.54 (1.13 to 2.10; P = 0.008) for pill. Approximately 15.6% to 46.8% of the association between WLSs and the T2D risk was attributed to weight changes. This study was limited by a single assessment of WLSs, heterogeneity within each WLS, and potential misclassification of the timing of weight loss and weight regain.

CONCLUSIONS

The current study showed that individuals with obesity who attempted to lose weight, regardless of the WLSs used, tended to gain less body weight and have a lower diabetes risk. In contrast, lean individuals who intentionally lost weight tended to gain more weight and have a higher diabetes risk. These data support the notion that intentional weight loss may not be beneficial for lean individuals and the use of WLSs for achieving weight loss shall be guided by medical indications only.

Oxford Food and Activity Behaviors 20-item questionnaire to assess personal weight management strategies: Development and testing

OBJECTIVE

The aim of this study was to develop a shortened Oxford Food and Activity Behaviors (OxFAB) questionnaire to identify the cognitive and behavioral strategies used by individuals during weight-management attempts.

METHODS

This study reduced an existing 117-item questionnaire (the original OxFAB questionnaire) through identifying clusters of techniques from the responses of 278 people living with obesity and, within those clusters, identifying the most representative question or questions. Questions were rephrased to cover multiple strategies at the domain level, with several alternative phrasings developed for new questions. Face validity was tested through think-aloud interviews with 12 people living with obesity. Questions were rephrased accordingly and tested using test-retest (n = 172). Prevalence- and bias-adjusted κ (PABAK) were calculated, and questions with PABAK < 0.41 were rewritten and evaluated in a new test-retest sample (n = 130).

RESULTS

OxFAB20 consists of 20 questions covering diet, physical activity, and cognitive strategies for weight management. Test-retest resulted in a mean PABAK score of 0.56 (SD = 0.14). Questions were revised where appropriate. The questionnaire is available for use via a CC-BY license.

CONCLUSIONS

The OxFAB20 questionnaire provides a practical tool for researchers to identify the cognitive and behavioral strategies used by individuals during attempts at weight control.

Nutrition recommendations for a healthy pregnancy and lactation in women with overweight and obesity - strategies for weight loss before and after pregnancy

A healthy eating pattern is recommended for all life stages and is central to achieving optimal pregnancy outcomes and successful lactation. The preconception period is a critical window of time during which good nutritional status benefits both the mother and the offspring. The ongoing overweight and obesity epidemic, especially in conjunction with poor nutritional status, presents maternal and infant health risks. Preconception and postpartum weight loss are routinely recommended in clinical practice. In this review, we discuss the nutritional recommendations for healthy weight loss during these periods. Unhealthy weight loss during preconception and for lactating women, can cause adverse maternal consequences that can impact the offspring.

Cardiovascular effects of intensive lifestyle intervention in adults with overweight/obesity and type 2 diabetes according to body weight time in range

BACKGROUND

We aimed to assess whether the cardiovascular effects of intensive lifestyle intervention (ILI) vary for those who can maintain the lower body weight after weight loss through ILI.

METHODS

In the secondary analysis of the Look AHEAD trial, we identified the status of weight loss for the participants in the ILI arm based on body weight time in range (TIR). These participants were allocated to three groups according to body weight TIR: 0% (n = 727), >0% to 50% (n = 656), and >50% to 100% (n = 811). For each group, cardiovascular outcomes were compared with matched participants receiving diabetes support & education (DSE) using 1:1 propensity score matching and Cox regression.

FINDINGS

During a median of 9·5 years of follow-up, participants with TIR of >50% to 100% can effectively maintain their body weight after weight loss through ILI; participants with TIR of 0% or >0% to 50% do not achieve or maintain weight loss. Compared with the corresponding matched participants in the DSE arm, participants with TIR of >50% to 100% in the ILI arm had a 45% lower risk of the primary outcome (HR 0·55, 95% CI 0·40-0·76), and no significant effects were found on the risk of the primary outcome in participants with TIR of 0% (HR 1·12, 95% CI 0·86-1·46) or >0% to 50% (HR 1·14, 95% CI 0·85-1·52).

INTERPRETATION

In adults with overweight/obesity and type 2 diabetes, ILI might help in lowering the risk of cardiovascular events when the lower body weight is maintained after weight loss.

FUNDING

None.

Consulting Obese and Overweight Patients for Nutrition and Physical Activity in Primary Healthcare in Poland

The aim of this study was to evaluate the dietary and physical activity counseling provided to adults by family doctors. Predictors of counseling in primary healthcare were identified. A cross-sectional study was conducted from January 2020 to December 2021 among 896 adult primary care patients in the city of Łódź [Lodz], Poland. Almost 36% of the respondents were advised to change their eating habits, and 39.6% were advised to increase their physical activity. In a multivariate logistic regression analysis, people in poor health with chronic diseases related to overweight and obesity and with two, three or more chronic diseases, respectively, received advice on eating habits from their GP twice and three times more often than people in good health with no chronic conditions (OR = 1.81; p < 0.05 and OR = 1.63; p < 0.05; OR = 3.03; p < 0.001). People in the age groups 30−39 years and 40−49 years (OR = 1.71; p < 0.05 and OR = 1.58; p < 0.05), widowed (OR = 2.94; p < 0.05), with two, three or more chronic diseases (OR = 1.92; p < 0.01 and OR = 3.89; p < 0.001), and subjectively assessing overweight and obesity (OR = 1.61; p < 0.01) had a better chance of receiving advice on physical activity. The study found a higher proportion of advice on diet and physical activity provided to overweight and obese patients by primary care physicians than in other studies; however, still not all receive the necessary counseling. GPs should advise all patients not to become overweight and obese, not only those already affected by the problem.

Predictors of Weight-Control Behavior in Healthy Weight and Overweight Korean Middle-Aged Women

Although obesity level is considered to influence weight-control behavior, few studies have examined how predictors of weight-control behavior differ according to obesity level. We compared the predictors of weight-control behavior in healthy weight and overweight middle-aged Korean women. This study used a comparative cross-sectional design. In total, 352 middle-aged women (131 overweight and 221 healthy) who visited community centers in eight Korean cities participated in the study. Participants completed self-report questionnaires concerning perceived health, body dissatisfaction, health-related concerns, self-esteem, and weight-control behavior. Scores for weight-control behavior in the overweight group were higher than those in the healthy weight group. Stepwise multiple regression showed that health-related concerns, body dissatisfaction, socioeconomic status, and self-esteem predicted weight-control behavior in the overweight group. Perceived health, socioeconomic status, meal regularity, health-related concerns, and age predicted weight-control behavior in the healthy weight group. The findings indicate that nursing strategies should differ according to obesity level to improve weight-control behavior in middle-aged women. In community or clinical settings, nurses are advised to develop customized weight control programs based on obesity levels in middle-aged women.