Promoting long-term weight control: does dieting consistency matter?

Factors associated with food choice among long-term weight loss maintainers

Background

The present study aimed to examine motivations for food choice among long‐term weight loss maintainers (WLM) in a widely used commercial weight management program.

Methods

A cross‐sectional study was employed where determinants of food choice were measured in the USA using validated scales: Food Choice Questionnaire, Consideration of Future Consequences, and Eating in the Absence of Hunger. Participants were 3806 WLM following a commercial weight management program (WW International, Inc.) who had maintained a weight loss ≥ 9.1 kg (mean 24.7 kg) for 3.3 years and had a body mass index (BMI) of 27.6 kg m². A control group of weight stable individuals with obesity (controls; n = 519) had a BMI of 38.9 kg m² and a weight change < 2.3 kg over the previous 5 years.

Results

WLM vs. controls made food decisions more based on health (18.9 vs. 16.3; η_p² = 0.052) and weight control (9.9 vs. 7.5; η_p² = 0.16) and less based on price (8.4 vs. 9.1; η_p² = 0.10). WLM also scored higher than controls with respect to considering future consequences of behaviours (44.3 vs. 38.4; η_p² = 0.060) and reported less external eating in the absence of hunger (7.1 vs. 7.5; η_p² = 0.058). Standard canonical coefficients indicated that making food choices based on weight (0.717) with less value placed on price (−0.33) and greater consideration of future consequences (0.262) contributed independently and most (overall r = 0.593; p = 0.0001) to discriminating WLM from controls.

Conclusions

In a widely used commercial weight management program, successful WLM reported food decisions based more on weight and less on price and considered future consequences of current behaviours.

Long‐term weight loss maintainers consume a diet that is low in calories and micronutrient rich, although the diverse factors that govern these food choices remain unclear.

The present study examined diverse factors associated with food choice among weight loss maintainers in a widely used commercial weight management program (WW International, Inc.) compared to weight stable individuals with obesity (“controls”).

Weight loss maintainers more than controls made food decisions based on health and weight control and less based on price. Both groups scored similarly in the role of convenience, mood, sensory appeal, natural content, familiarity and ethical concerns.

Weight loss maintainers were overall more likely to consider future consequences.

In a widely used commercial weight management program (WW International, Inc.), successful weight loss maintainers reported food decisions based more on weight and health and less on price. They also considered future consequences of current behaviours.

Sustaining Regular Exercise During Weight Loss Maintenance: The Role of Consistent Exercise Timing

BACKGROUND

Exercising at a consistent versus variable time of day cross-sectionally relates to greater moderate to vigorous physical activity (MVPA) among weight loss maintainers. This study evaluated the relationships between exercise timing and both MVPA levels and habit strength, as well as stability in exercise timing, over 1 year among maintainers in the National Weight Control Registry.

METHODS

Participants (n = 709) completed questionnaires assessing exercise timing, MVPA, and exercise automaticity (a measure of habit) at baseline and 1-year follow-up. At each assessment, participants were labeled temporally consistent exercisers if >50% of their exercise sessions per week occurred in one time window: early morning, late morning, afternoon, or evening. Participants exercising consistently during the same window at both assessments were labeled as having stable patterns.

RESULTS

Temporally consistent exercise at baseline, regardless of its specific time, related to greater MVPA over time (Ps< .05). Approximately half of temporally consistent exercisers at baseline exhibited stable patterns. Early morning exercise and greater exercise automaticity at baseline predicted stable patterns (Ps< .005). Temporally consistent exercise, especially during the early morning, related to greater automaticity across time (Ps< .01).

CONCLUSIONS

Consistent exercise timing may help maintainers accrue more MVPA. Consistent early morning exercise was most strongly related to exercise automaticity and routine stability.

Development and validation of the Highly Effective Health Behavior Pattern Inventory - Short Form

OBJECTIVES

The purpose of this study was to develop and validate a short form (SF) of the highly effective health behavior pattern inventory (HEBPI) for chronic disease patients for comfort to use.

METHODS

HEBPI-SF is a self-reported questionnaire based on highly effective health behaviors associated with building healthy habits. HEBPI-SF was validated by calculating adjusted odds ratios (aOR) for the 12 HEBPI-SF health behavior subscales and the maintenance of the 12 corresponding health habits.

RESULTS

HEBPI-SF developed in this study comprised 12 subscales and 53 items, utilizing patient data (N = 724) derived from the original HEBPI (12 subscales and 131items). HEBPI-SF demonstrated high reliability (Cronbach's α of 0.703-0.859) and showed that the 12 health behaviors included in the HEBPI are associated with the maintenance of the corresponding health habits (aOR: 2.29-8.42). The scores of the HEBPI-SF showed a positive correlation with physical, mental, social, spiritual and general health status, quality of life, and self-management strategies.

DISCUSSION

HEBPI-SF is a reliable tool for the assessment of health behaviors of chronically ill patients. Considering previous findings of simple health behaviors significantly affecting health status, this survey tool for the assessment of health behaviors is useful for promotion and maintenance of healthy habits.

The neurobiology of abstinence-induced reward-seeking in males and females

Drugs of abuse and highly palatable foods (e.g. high fat or sweet foods) have powerful reinforcing effects, which can lead to compulsive and addictive drives to ingest these substances to the point of psychopathology and self-harm--specifically the development of Substance Use Disorder (SUD) and obesity. Both SUD and binge-like overeating can be defined as disorders in which the salience of the reward (food or drug) becomes exaggerated relative to, and at the expense of, other rewards that promote well-being. A major roadblock in the treatment of these disorders is high rates of relapse after periods of abstinence. It is common, although not universal, for cue-induced craving to increase over time with abstinence, often triggered by cues previously paired with the reinforcing substance. Accumulating evidence suggests that similar neural circuits and cellular mechanisms contribute to abstinence-induced and cue-triggered seeking of drugs and palatable food. Although much research has focused on the important role of corticolimbic circuitry in drug-seeking, our goal is to expand focus to the more recently explored hypothalamic-thalamic-striatal circuitry. Specifically, we review how connections, and neurotransmitters therein, among the lateral hypothalamus, paraventricular nucleus of the thalamus, and the nucleus accumbens contribute to abstinence-induced opioid- and (high fat or sweet) food-seeking. Given that biological sex and gonadal hormones have been implicated in addictive behavior across species, another layer to this review is to compare behaviors and neural circuit-based mechanisms of abstinence-induced opioid- or food-seeking between males and females when such data is available.

Impact of Hurricane Harvey on the Growth of Low Income, Ethnic Minority Adolescents

OBJECTIVE

This study examined the differential impact of Hurricane Harvey on adolescent standardized Body Mass Index (zBMI), physical activity, diet, and perceived stress.

METHODS

Prior to Hurricane Harvey, 175 ethnic minority adolescents were recruited from an independent school district in Houston. Height and weight were directly measured. The School Physical Activity and Nutrition Questionnaire assessed diet and physical activity. Stress was assessed with the Perceived Stress Scale. High hurricane impact was classified as at least 1 affirmative response to house damage, rescue, displacement, or going without food, water, or medicine. Repeated measures such as ANCOVA models were developed to assess differences in zBMI, physical activity, diet, and stress between the hurricane impact groups. Regression models were used to assess stress as a mediator of the hurricane impact and zBMI change relationship.

RESULTS

Students who were highly impacted by the hurricane had a greater decrease in zBMI than those less impacted from pre-hurricane to 15 weeks post-hurricane (95% CI 0.02 to 0.25, p<0.05). Physical activity and diet did not differ by impact. Perceived stress at 3 weeks post-hurricane mediated the impact and zBMI change relationship (β=-0.04 95% CI -0.12 to -0.002).

CONCLUSION

The decrease in zBMI among highly impacted students warrants further monitoring. Perceived stress, immediately following the hurricane, impacted student growth months later.

Morning diurnal preference and food intake: a Mendelian randomization study

BACKGROUND

Poor dietary choices may underlie known associations between having an evening diurnal preference and cardiometabolic diseases. Assessing causal links between diurnal preference and food intake is now possible in Mendelian randomization (MR) analyses.

OBJECTIVES

We aimed to use a 2-sample MR to determine potential causal effects of genetic liability to a morning preference on food intake. We also examined potential causal effects of a morning preference on objectively captured response performances to email-administered 24-h diet recalls.

METHODS

We used genetic variants associated with a morning preference from a published genome-wide association meta-analysis. Our outcomes included 61 food items with estimates from a food-frequency questionnaire in the UK Biobank (n = 361,194). For significant findings, we repeated the analysis using intake estimates from modified 24-h diet recalls in a subset of overlapping participants (n = 146,086). In addition, we examined 7 response performance outcomes, including the time and duration of responses to 24-h diet recalls (n = 123,035). MR effects were estimated using an inverse-variance weighted analysis.

RESULTS

Genetic liability to a morning preference was associated with increased intake of 6 food items (fresh fruit, alcohol with meals, bran cereal, cereals, dried fruit, and water), decreased intake of 4 food items (beer plus cider, processed meat, other cereals [e.g., corn or frosted flakes], and full cream milk), increased temperature of hot drinks, and decreased variation in diet (PFalse Discovery Rate < 0.05). There was no evidence for an effect on coffee or tea intake. Findings for fresh fruit, beer plus cider, bran cereal, and cereal were consistent when intakes were estimated by 24-h diet recalls (P < 0.05). We also identified potential causal links between a morning preference with earlier timing and a shorter duration for completing email-administered 24-h diet recalls.

CONCLUSIONS

Our findings provide evidence for a potentially causal effect of a morning preference with the increased intake of foods known to constitute a healthy diet, suggesting possible health benefits of adopting a more morning diurnal preference.

Successful weight loss maintenance: A systematic review of weight control registries

Weight loss maintenance is a major challenge for obesity treatment. Weight control registries can be useful in identifying psychological and behavioural factors that could contribute to better long-term success. The objective of this study is to describe the existing weight control registries and their participants and identify correlates of weight loss maintenance. A comprehensive search of peer-reviewed articles published until November 2018 was conducted in PubMed, Web of Science, and Scopus. Studies that reported results from weight control registries were considered. Fifty-two articles, corresponding to five registries (the United States, Portugal, Germany, Finland, and Greece), were included. Registries differed in inclusion criteria and procedures. Of 51 identified weight loss and maintenance strategies, grouped in 14 domains of the Oxford Food and Activity Behaviors taxonomy, the following were the most frequently reported: having healthy foods available at home, regular breakfast intake, increasing vegetable consumption, decreasing sugary and fatty foods, limiting certain foods, and reducing fat in meals. Increased physical activity was the most consistent positive correlate of weight loss maintenance. To our knowledge, this is the first systematic review of information about successful weight loss maintenance obtained from weight control registries. Key common influential characteristics of success were identified, which can inform future prospective studies and weight management initiatives.

Behavioral and Psychological Strategies of Long-Term Weight Loss Maintainers in a Widely Available Weight Management Program

OBJECTIVE

The study's purpose was to use validated questionnaires to identify novel behavioral and psychological strategies among weight loss maintainers (WLMs) in a commercial weight management program.

METHODS

Participants were 4,786 WLMs in WW (formerly Weight Watchers, New York, New York) who had maintained weight loss  ≥ 9.1 kg (24.7 kg/23.8% weight loss on average) for 3.3 years and had a current mean BMI of 27.6 kg/m² . A control group of 528 weight-stable individuals with obesity had a mean BMI of 38.9 kg/m² and weight change  < 2.3 kg over the previous 5 years.

RESULTS

WLMs versus Controls practiced more frequent healthy dietary choices (3.3 vs. 1.9; η p 2  = 0.37), self-monitoring (2.6 vs. 0.7; η p 2  = 0.30), and psychological coping (2.5 vs. 1.1; η p 2  = 0.25) strategies. WLMs also reported more willingness to ignore food cravings (4.4 vs. 3.5; η p 2  = 0.16) and had greater habit strength for healthy eating (5.3 vs. 3.2;  η p 2  = 0.21). Standard canonical coefficients indicated that dietary (0.52), self-monitoring (0.40), and psychological (0.14) strategies as well as habit strength for healthy eating (0.15) contributed independently and most (49.5% of variance) to discriminating groups.

CONCLUSIONS

In a widely available weight management program, more frequent practice of healthy dietary, self-monitoring, and psychological coping strategies as well as development of greater habit strength for healthy eating differentiated long-term WLMs from weight-stable individuals with obesity.

Associations of Objectively Measured Physical Activity and Sleep with Weight Loss Maintenance: A Preliminary Study of Japanese Adults

Maintaining weight loss is considerably more challenging than losing weight. Most previous studies on weight loss maintenance have been conducted in Western countries and have assessed physical activity and sleep with the use of questionnaires. This preliminary study investigated the associations of objectively measured physical activity and sleep with weight loss maintenance among 25 Japanese adults who had intentionally lost ≥ 10% of their original weight. Participants wore tri-axial accelerometers on their waists and sleep monitors on their wrists for two weeks to measure their physical activity and sleep, respectively. A linear regression adjusted for sex, age, maximum weight, and time since losing weight was performed to investigate these associations. Participants had a mean body mass index of 23.4 kg/m² and a median weight loss of 12.5%. Compared to those who maintained < 12.5% weight loss, those who maintained ≥ 12.5% weight loss slept longer (adjusted mean difference: 66.1 min/night, 95% confidence interval (CI): −14.0, 146.3 min/night, p = 0.10) and performed less moderate-to-vigorous physical activity (adjusted mean difference: −21.7 min/day, 95% CI: −58.0, 14.5 min/day, p = 0.22). Though statistical power was limited, sleep behavior may be an important modifiable factor that facilitates weight loss maintenance. Our findings can be used to establish a well-designed study to confirm this association.

Mediators of Weight Loss Maintenance in the Keep It Off Trial

Background

An important step toward enhancing the efficacy of weight loss maintenance interventions is identifying the pathways through which successful interventions such as the Keep It Off trial have worked.

Purpose

This study aimed to assess the viability of mediated relationships between the Keep It Off Guided intervention, conceptually and empirically grounded potential mediators, and weight. Repeated measurement of mediators and weight enabled documentation of the temporal ordering of intervention delivery and changes in mediators and in weight among participants randomized to the Guided intervention or Self-Directed comparison group.

Methods

Total, direct, and indirect effects of the Guided intervention on weight change were calculated and tested for significance. Indirect effects were comprised of the influence of the intervention on three change scores for each mediator and the relationship between mediator changes and weight changes 6 months later.

Results

Guided intervention participants regained about 2% less weight over 24 months than Self-Directed participants. Starting daily self-weighing accounted for the largest share of this difference, followed by not stopping self-weighing.

Conclusions

Daily self-weighing mediated 24-month weight loss maintenance.

Trial Registration Number

The trial is registered withClinicalTrials.gov (Identifier: NCT00702455www.clinicaltrials.gov/ct2/show/NCT00702455).

Dietary Behaviour Is Associated with Cardiometabolic and Psychological Risk Indicators in Female Hospital Nurses-A Post-Hoc, Cross-Sectional Study

Unfavourable dietary behaviours of female nurses, especially among shift-working nurses, including high snacking frequency, short fasting period and large day-to-day energy intake variability may be linked with adverse health. In this study we: (1) examined the relationship between dietary behaviour and cardiometabolic and psychological health in female nurses; and, (2) compared dietary behaviour, cardiometabolic and psychological health between shift-working and non-shift-working female nurses. A total of 73 nurses had their cardiometabolic health indicators evaluated and completed psychological health questionnaires; 55 completed a 3-day dietary log. Associations between dietary behaviour and health measures were examined using Spearman’s partial correlation analysis. Analysis of covariance (ANCOVA) was used to compare dietary behaviour and health indicators between shift- and non-shift-working nurses. The majority of snacks consumed by nurses (70%) were unhealthy snacks (e.g., chocolate and chips), and higher snacking frequency was associated with greater percent body fat (r(50) = 0.287, p = 0.039), and worse mood-tension (r(48) = 0.327, p = 0.021) and anger-hostility (r(48) = 0.289, p = 0.042) scores. Day-to-day energy intake variability was positively associated with body mass index (BMI, r(50) = 0.356, p = 0.010) and waist circumference (r(50) = 0.283, p = 0.042). Shift-working nurses exhibited shorter fasting duration, larger day-to-day energy intake variability and higher total mood disturbance score when compared to their non-shift-working colleagues (all p < 0.05). The results of the present study suggested that addressing dietary behaviours may improve the cardiometabolic and psychological health of female nurses. Shift-working nurses may require a more specific dietary program to improve their psychological health.

Relationship of Consistency in Timing of Exercise Performance and Exercise Levels Among Successful Weight Loss Maintainers

OBJECTIVE

This study aimed to evaluate whether consistency in time of day that moderate- to vigorous-intensity physical activity (MVPA) is performed relates to MVPA levels among successful weight loss maintainers in the National Weight Control Registry.

METHODS

Participants (n = 375) reporting MVPA on ≥ 2 d/wk completed measures of temporal consistency in physical activity (PA) (> 50% of MVPA sessions per week occurring during the same time window: early/late morning, afternoon, or evening), PA levels, PA automaticity, and consistency in cues underlying PA habit formation (e.g., location).

RESULTS

Most (68.0%) participants reported temporally consistent MVPA. These individuals reported higher MVPA frequency (4.8 ± 1.6 vs. 4.4 ± 1.5 d/wk; P = 0.007) and duration (median [IQR]: 350.0 [200.0-510.0] vs. 285.0 [140.0-460.0] min/wk; P = 0.03), and they were more likely to achieve the national MVPA guideline (≥ 150 min/wk) than temporally inconsistent exercisers (86.3% vs. 74.2%, P = 0.004). Among temporally consistent exercisers, 47.8% were early-morning exercisers; MVPA levels did not differ by time of day of routine MVPA performance (P > 0.05). Greater automaticity and consistency in several cues were related to greater MVPA among all participants.

CONCLUSIONS

Most participants reported consistent timing of MVPA. Temporal consistency was associated with greater MVPA, regardless of the specific time of day of routine MVPA performance. Consistency in exercise timing and other cues might help explain characteristic high PA levels among successful maintainers.

The Importance of Creating Habits and Routine

One of the greatest challenges to lifestyle medicine is patient adherence. Lifestyle diseases inherently require lifetime prevention and treatment. Therefore, adherence to lifestyle medicine recommendations must also be long-term. Long-term adherence implies that a routine incorporating health recommendations has been developed. Instead of focusing on the immediacy of adherence in lifestyle changes, health care providers could consider helping patients develop a routine to slowly incorporate those changes. This perspective may enable greater long-term adherence to lifestyle change recommendations.

Understanding everyday strategies used to manage indulgent food consumption: A mixed-methods design

To maintain a healthy body weight or support weight loss efforts, dietary self-management must allow for the limitation of tempting high energy-dense foods. We were interested in people's implementation of day-to-day strategies in order to successfully manage their indulgent food and beverage consumption. Participants from the Swansea area, UK (N = 25; M_age = 37; 68% male) were divided into four focus groups. The average BMI was within the healthy range (23 kg/m²). Each group discussed the approaches that they used to manage their consumption of indulgent foods and drinks. Group discussions were then transcribed, thematically analysed and independently reviewed by a second researcher. In a follow-up phase, participants were asked to rate how often they used the identified strategies and to rate the perceived effectiveness of any that applied to them. The thematic analysis revealed four major themes: Exercise, Cognitive Strategies, Availability and Meal Formation. Variability in the frequency with which strategies were used and perceived as effective was evident. Notably, participants tended to use multiple strategies and even lean participants who did not identify themselves as 'dieters' none-the-less employed a variety of strategies to successfully manage their exposure to and consumption of tempting foods. The findings suggest that dietary advice could be improved by taking into account the strategies for managing indulgent food consumption that are frequently used by individuals, as well as those that are perceived as effective.

Does diet strictness level during weekends and holiday periods influence 1-year follow-up weight loss maintenance? Evidence from the Portuguese Weight Control Registry

There is not much evidence about how diet strictness during weekends and holidays influence long-term weight loss maintenance. Our aim was to examine how dieting more or less strictly during weekends and holidays (vs. weekdays and non-holiday periods) influence weight loss maintenance.Participants (n = 108) from the Portuguese Weight Control Registry indicated whether they had a more or less strict diet regimen during weekends compared to weekdays. A similar question about holiday and non-holiday period' diet regimen was answered. Weight and height were measured at baseline and 1y follow-up. A 3% maximum weight variation defined participants as "non-regainers".General level on dieting strictness on weekends vs. weekdays (r = - 0.28, p < 0.01) and holidays vs. non-holidays (r = - 0.33, p < 0.001) predicted 1y weight change.Participants who reported being less strict on weekends (OR = 0.34, 95% CI: 0.15-0.81) were more likely to be non-regainers when compared with the ones who reported being more strict on weekends. Non-significant results were found during holidays (OR = 0.47, 95% CI: 0.20-1.09).Adopting a less strict diet regimen during weekends, when compared to weekdays, was a behavioral strategy associated with long-term weight management in our sample.

Variability in Weight Change Early in Behavioral Weight Loss Treatment: Theoretical and Clinical Implications

OBJECTIVE

Response early in weight loss treatment predicts long-term weight change. Weight variability, independent of absolute early weight change, may also relate to long-term outcomes. This study examined whether weight variability early in treatment predicted later weight loss and maintenance.

METHODS

Participants were 183 completers of a yearlong behavioral weight loss program (mean age = 51, 81% female, 69% white, mean BMI = 35  kg/m2 ). Weight variability was calculated using weights from the first 6 and 12 weekly treatment sessions. Multiple linear regressions examined whether weight variability predicted subsequent weight change 6, 12, and 24 months later.

RESULTS

Weight variability over 6- and 12-week periods predicted less subsequent weight loss at 12 months (6-week: β = 0.18, P = 0.02; 12-week: β = 0.33, P < 0.01) and 24 months (6-week: β = 0.17, P = 0.03; 12-week: β = 0.15, P = 0.05). Relationships held when adjusting for covariates. Weight variability was more strongly associated with 6-month weight change in men than women (β = 0.27, P = 0.01).

CONCLUSIONS

Elevated weight variability early in a weight loss program predicted poor long-term outcomes, possibly reflecting inconsistent weight control behaviors. Tracking weight variability could prove useful for improving treatment outcomes.

Attenuating the Biologic Drive for Weight Regain Following Weight Loss: Must What Goes Down Always Go Back Up?

Metabolic adaptations occur with weight loss that result in increased hunger with discordant simultaneous reductions in energy requirements—producing the so-called energy gap in which more energy is desired than is required. The increased hunger is associated with elevation of the orexigenic hormone ghrelin and decrements in anorexigenic hormones. The lower total daily energy expenditure with diet-induced weight loss results from (1) a disproportionately greater decrease in circulating leptin and resting metabolic rate (RMR) than would be predicted based on the decline in body mass, (2) decreased thermic effect of food (TEF), and (3) increased energy efficiency at work intensities characteristic of activities of daily living. These metabolic adaptations can readily promote weight regain. While more experimental research is needed to identify effective strategies to narrow the energy gap and attenuate weight regain, some factors contributing to long-term weight loss maintenance have been identified. Less hunger and greater satiation have been associated with higher intakes of protein and dietary fiber, and lower glycemic load diets. High levels of physical activity are characteristic of most successful weight maintainers. A high energy flux state characterized by high daily energy expenditure and matching energy intake may attenuate the declines in RMR and TEF, and may also result in more accurate regulation of energy intake to match daily energy expenditure.

Behavioral Medicine Review: Strategic Management of Diabetes Risk

There is widespread public health concern about the upsurge in diabetes and its cardiometabolic comorbidities. Unfortunately, too many patients still do not receive best practices care. This review discusses some key contributing dynamics as well as considerations for progress toward the more comprehensive, strategic management of diabetes and its associated risks.

Caloric Intake on the Sabbath: A Pilot Study of Contributing Factors to Obesity in the Orthodox Jewish Community

The American Orthodox Jewish community has specific cultural factors that may contribute to overweight and obesity. This study aimed to look at caloric intake on the Sabbath and its contribution to overweight and obesity. Twelve married or previously married women who identify themselves as Orthodox Jews were recruited to do 24-h food recalls over the phone. The participants were divided into three weight groups (normal, overweight, and obese) based on their BMI. The overweight and obese participants' data were combined into one group for the purposes of statistical testing. Paired t tests looking at the data for all participants showed significantly great caloric intake during an average Sabbath day than an average weekday [t(4) = 7.58, p < 0.001]. A repeated-measures ANOVA showed significantly greater energy intake on the Sabbath for the overweight-obese women compared to the normal weight women [F(1) = 7.83, p = 0.02]. No statistical difference was seen between the weekday energy intake of the normal weight women as compared to the combined group of overweight-obese women [F(1) = 0.501, p = 0.499]. These results support the hypotheses that all groups eat significantly more on the Sabbath than on weekdays, and overweight and obese individuals eat significantly more on the Sabbath than normal weight individuals. This supports the theory that caloric intake on the Sabbath is a contributing factor to overweight and obesity within the American Orthodox Jewish community.

Energy intake highs and lows: how much does consistency matter in weight control?

Behavioural weight control programmes recommend adherence to daily energy intake goals, yet also allow for flexibility in intake across days. Evidence is lacking as to whether intake consistency is important for weight control. The current study explored the relation between day-to-day intake consistency and weight loss in the context of behavioural weight loss treatment and examined the relationship between variability in intake and several factors known to be associated with weight control success. Participants (N =  283) enrolled in a 12-month behavioural weight loss programme completed 24-h recalls of dietary intake and psychological measures. At the end of treatment, low intake variability and greater weight loss were associated, but variability was not predictive of weight loss independent of mean intake in continuous analyses. Interestingly, participants who met the programme goal of ≥10% weight loss had less intake variability compared to those who lost <10%, although groups did not differ significantly on mean intake. Results suggest that daily intake consistency may facilitate successful weight loss for some. Additionally, autonomous motivation for weight management and cognitive dietary restraint were inversely related to end-of-treatment intake variability. Additional research is needed to examine whether recommendations to limit intake variability during behavioural weight loss treatment improve long-term weight control.

Macronutrient Content of the Diet: What Do We Know About Energy Balance and Weight Maintenance?

The 2013 AHA/ACC Clinical Guideline for the Management of Overweight and Obesity recommends a reduced energy diet for weight loss regardless of the macronutrient content. However, diet composition may affect the maintenance of weight loss. In general, a healthful dietary pattern with reduced portion sizes, low energy dense foods, and physical activity are successful for many. Certain populations, such as those with insulin resistance, may find reductions in carbohydrate and higher levels of unsaturated fats to be more effective and promote greater adherence. Of importance is that metabolic adaptations following weight loss also may impact weight loss maintenance and should be considered in the transition from weight loss to weight stabilization. Thus, weight loss and weight maintenance strategies are both important in an intervention for sustaining long-term behavior change.

Seasonal cycles in food purchases and changes in BMI among South Africans participating in a health promotion programme

Objective

Improving diet quality is a key factor for promoting population health. Social norms can support or undermine these efforts. The present study aimed to investigate the relationship between seasonal variation in food purchases and BMI.

Design

The study population comprises members of a South African health promotion programme. Data come from scanner data of food purchases by 400 000 enrolled households at supermarkets and repeated individual surveys (about 500 000 participants) between 2009 and 2013.

Results

Members in the health promotion programme spent 16·7 % of total food expenditure on nutritionally undesirable foods (sugar-sweetened beverages, candy, ice cream, etc.) and 24·7 % on healthy foods (fruit/vegetables, whole grains, non-fat dairy, etc.). Fruits and vegetables accounted for 13·5 % of purchases (half of all healthy food spending). Yet there were pronounced seasonal variations, with December being the peak month for unhealthy food purchases, which were 40 % higher than in January. This holiday peak was associated with short-term weight gain, but average body mass did not revert to pre-holiday levels. From 2009 to 2013, respondents gained about 0·13 BMI units per year (0·43 kg for men, 0·30 for women). From November to January alone, the increase was 0·1 BMI units for men (0·35 kg) and 0·8 BMI units for women (0·20 kg).

Conclusions

Purchases of nutritionally undesirable foods peak in December and are accompanied by weight gain from November to January. Despite weight loss after January, the November to January weight gain accounts for 60–70 % of the annual gain.

Dietary patterns and weight change: 15-year longitudinal study in Australian adults

BACKGROUND

Dietary intake is one of the most modifiable risk factors associated with obesity. However, data on the relationship between dietary patterns and long-term weight change are limited.

PURPOSE

We therefore investigated the association between dietary patterns and 15-year weight change in a sample of 1186 Australian adults (1992-2007).

METHODS

We measured body weight and collected data on socio-demographic and lifestyle characteristics in 1992 and 2007. Applying principal component analysis to 38 food groups from a food frequency questionnaire collected at baseline, we identified two dietary patterns: 'meat-and-fat' and 'fruit-and-vegetable.' Using generalized estimating equations, multivariable regression models, stratified by sex, were adjusted for concurrent changes in socio-demographic and lifestyle variables.

RESULTS

The average increase in body weight of men in the highest tertile of the meat-and-fat pattern was more than twice that of men in the lowest tertile; mean weight change (95 % CI): 4.8 (-0.1, 9.7) kg versus 2.3 (-2.6, 7.1) kg, P-for-trend = 0.02. In contrast, average weight gain of men in the highest tertile of the fruit-and-vegetable pattern was only about half that of men in the lowest tertile; mean weight change (95 % CI): 2.9 (-2.0, 7.8) kg versus 5.4 (-1.5, 10.4) kg, P-for-trend = 0.02. Among women, dietary patterns were not related to weight change.

CONCLUSIONS

These dietary patterns predict change in body weight in men, but not in women. In this cohort, a dietary pattern high in fruit and vegetables was related to less weight gain in men than a dietary pattern high in meat and fat.

Ghrelin enhances cue-induced bar pressing for high fat food

Ghrelin is an orexigenic hormone produced by the stomach that acts on growth hormone secretagogue receptors (GHSRs) both peripherally and centrally. The presence of GHSRs in the ventral tegmental area (VTA) suggests that ghrelin signaling at this level may increase the incentive value of palatable foods as well as other natural and artificial rewards. The present investigation sought to determine if ghrelin plays a role in relapse to such foods following a period of abstinence. To achieve this, thirty-six male Long Evans rats were trained to press a lever to obtain a high fat chocolate food reward on a fixed ratio schedule of 1. Following an extinction period during which lever presses were not reinforced, rats were implanted with a cannula connected to a minipump that continuously delivered ghrelin, a GHSR antagonist ([d-Lys-3]-GHRP-6), or saline in the VTA for 14days. One week later, food reward-associated cues, food reward priming, and an overnight fast were used to induce reinstatement of the lever pressing response. Our results indicate that intra-VTA ghrelin enhances cue-induced reinstatement of responses for palatable food pellets. To the extent that the reinstatement paradigm is considered a valid model of relapse in humans, this suggests that ghrelin signaling facilitates relapse to preferred foods in response to food cues through GHSR signaling in the VTA.

Personality and Situation Predictors of Consistent Eating Patterns

INTRODUCTION

A consistent eating style might be beneficial to avoid overeating in a food-rich environment. Eating consistency entails maintaining a similar dietary pattern across different eating situations. This construct is relatively under-studied, but the available evidence suggests that eating consistency supports successful weight maintenance and decreases risk for metabolic syndrome and cardiovascular disease. Yet, personality and situation predictors of consistency have not been studied.

METHODS

A community-based sample of 164 women completed various personality tests, and 139 of them also reported their eating behaviour 6 times/day over 10 observational days. We focused on observations with meals (breakfast, lunch, or dinner). The participants indicated if their momentary eating patterns were consistent with their own baseline eating patterns in terms of healthiness or size of the meal. Further, participants described various characteristics of each eating situation.

RESULTS

Eating consistency was positively predicted by trait self-control. Eating consistency was undermined by eating in the evening, eating with others, eating away from home, having consumed alcohol and having undertaken physical exercise. Interactions emerged between personality traits and situations, including punishment sensitivity, restraint, physical activity and alcohol consumption.

CONCLUSION

Trait self-control and several eating situation variables were related to eating consistency. These findings provide a starting point for targeting interventions to improve consistency, suggesting that a focus on self-control skills, together with addressing contextual factors such as social situations and time of day, may be most promising. This work is a first step to provide people with the tools they need to maintain a consistently healthy lifestyle in a food-rich environment.

A Cognitive Profile of Obesity and Its Translation into New Interventions

Change your lifestyle: decrease your energy intake and increase your energy expenditure, is what obesity experts tell people who need to lose weight. Though the advice might be correct, it appears to be extremely difficult to change one’s lifestyle. Unhealthy habits usually are ingrained and hard to change, especially for people with an “obese cognitive profile.” Knowledge of the cognitive mechanisms that maintain unhealthy eating habits is necessary for the development of interventions that can change behavior effectively. This paper discusses some cognitive processes that might maintain unhealthy eating habits and make healthier eating difficult, like increased food cue reactivity, weak executive skills and attention bias. An effort is also done to translate these basic scientific findings into new interventions which aim to tackle the sabotaging cognitive processes. Preliminary studies into the effectiveness of these interventions, if available, are presented.

Are Trait–Outcome Associations Caused by Scales Or Particular Items? Example Analysis of Personality Facets and Bmi

In personality research, trait–outcome associations are often studied by correlating scale sum scores with an outcome. For example, an association between the NEO Impulsiveness scale and body mass index (BMI) is often interpreted to pertain to underlying trait Impulsiveness. We propose that this expectation can be corroborated by testing for Spearman's theorem of indifference of indicator. Namely, an underlying trait–outcome association should not depend on the specific items (i.e. indicators) used to measure the trait. To test this theorem, we outline an indicator exclusion procedure and demonstrate its viability using a simulation design. We then apply this procedure to test personality–BMI associations for indifference of indicator in a large population–based sample of adult Estonians (N = 2581) using self–ratings and informant ratings obtained with the NEO Personality Inventory–3. Our results show that the N5: Impulsiveness–BMI association mostly depends on two eating–related items, suggesting that the trait associated with BMI may be narrower than the trait the N5: Impulsiveness scale is supposed to measure. Associations between BMI, E3: Assertiveness and C2: Order seem to pertain to the trait. In sum, testing for indifference of indicator provides a potentially useful method to clarify trait–outcome relationships. R scripts are provided that implement the indicator exclusion procedure. Copyright © 2015 European Association of Personality Psychology

A novel classification paradigm for understanding the positive and negative outcomes associated with dieting

There are significant discrepancies regarding use of the term “dieting.” Common definitions of dieting include behavior modifications arguably moderate (e.g., increasing vegetable consumption), those considered more extreme (e.g., fasting), and more ambiguous behaviors (e.g., reducing carbohydrates). Adding to confusion are findings demonstrating that many individuals endorsing dieting do not actually reduce caloric intake. (1) Thus, “dieting” refers to behaviors ranging from moderate to extreme, attempts to reduce intake without objective caloric decrease, and caloric reductions without associated distress. Unfortunately, existing measures collapse together these widely discrepant experiences. As a result, there is poor coordination between the eating disorder and obesity fields in terms of dieting recommendations. Some suggest that dieting contributes to development of disordered eating and obesity; others argue that dieting is necessary for reducing excess weight and health risk. Without clearly defined dieting constructs, neither the eating disorders nor obesity fields can progress towards effective prediction, prevention, or treatment. We propose a novel classification scheme, the “Psycho-behavioral Dieting Paradigm”, which improves upon existing models by differentiating the behavioral and psychological dimensions associated with discrepant dieting experiences and categorizing the interactions between these domains. This model is intended to categorize individuals that endorse dieting, independent of dieting goals. At present, this model is only meant to describe dieting patterns associated with different outcomes, rather than to suggest causal relationships between these patterns and eating disorder and obesity risk. Below we describe this paradigm and provide directions for research.

What distinguishes weight loss maintainers of the German Weight Control Registry from the general population?

OBJECTIVE

Differences between successful long-term weight loss maintainers and the general population with regard to eating and weighing habits, non-normative eating behaviors, and eating-related and general psychopathological parameters are unknown.

METHODS

Self-identified weight loss maintainers from the German Weight Control Registry (GWCR, n = 494) were compared with a representative sample of the general German population (n = 2,129). The samples did not differ in current BMI. Using the same assessment instruments in both cohorts, a variety of eating-related and psychological variables were determined.

RESULTS

The GWCR participants reported more self-weighing and higher eating frequency but less hot meal consumption and more eating-out-of-home. Binge eating, compensatory behaviors, and concerns about shape and weight were reported more often by successful weight loss maintainers. Scores of depression and worrying about health were slightly higher whereas severity of somatic symptoms was less pronounced in the GWCR participants.

CONCLUSIONS

Overall, our data suggest that successful weight loss maintainers are characterized by more concerns about shape and weight, greater binge eating frequency, and higher use of compensatory behaviors. The latter suggests that weight loss maintenance might not only be achieved by healthy strategies but also by non-normative behaviors which might increase the vulnerability for weight regain.

Inactivation of the nucleus accumbens core or medial shell attenuates reinstatement of sugar-seeking behavior following sugar priming or exposure to food-associated cues

Re-exposure to either palatable food or to conditioned stimuli associated with food is known to reinstate food-seeking after periods of abstinence. The nucleus accumbens core and shell are important for reinstatement in both food- and drug-seeking paradigms, although their potential differential roles have been difficult to delineate due to methodological differences in paradigms across laboratories. The present studies assessed the effects of temporary inactivation of the core or shell on priming- and cue-induced reinstatement of food-seeking in identically-trained rats. Inactivation of either the nucleus accumbens core (Experiment 1A; N = 10) or medial shell (Experiment 1B; N = 12) blocked priming-induced reinstatement in an equivalent manner. Similarly, inactivation of the core or medial shell (Experiments 2A & 2B; N = 11 each) also blocked cue-induced reinstatement, although there was also a significant treatment day X brain region X drug order interaction. Specifically, rats with core inactivation reinstated lever-pressing on the vehicle injection day regardless of whether that was their first or second test, whereas rats that had medial shell inactivation on the first day did not significantly reinstate lever-pressing on the second day of testing (when they received vehicle). Yohimbine, while a reportedly robust pharmacological stressor, was ineffective at inducing reinstatement in the current stress-induced reinstatement procedure. These data suggest that both the nucleus accumbens core and shell serve important roles in reinstatement of food-seeking in response to priming and cues.

Weight rhythms: weight increases during weekends and decreases during weekdays

BACKGROUND/AIMS

The week's cycle influences sleep, exercise, and eating habits. An accurate description of weekly weight rhythms has not been reported yet - especially across people who lose weight versus those who maintain or gain weight.

METHODS

The daily weight in 80 adults (BMI 20.0-33.5 kg/m(2); age, 25-62 years) was recorded and analysed to determine if a group-level weekly weight fluctuation exists. This was a retrospective study of 4,657 measurements during 15-330 monitoring days. Semi-parametric regression was used to model the rhythm.

RESULTS

A pattern of daily weight changes was found (p < 0.05), with higher weight early in the week (Sunday and Monday) and decreasing weight during the week. Increases begin on Saturday and decreases begin on Tuesday. This compensation pattern was strongest for those who lost or maintained weight and weakest for those who slowly gained weight.

CONCLUSION

Weight variations between weekends and weekdays should be considered as normal instead of signs of weight gain. Those who compensate the most are most likely to either lose or maintain weight over time. Long-term habits may make more of a difference than short-term splurges. People prone to weight gain could be counselled about the importance of weekday compensation.

Healthy strategies for successful weight loss and weight maintenance: a systematic review

The rates of overweight and obesity are rising in Canada and worldwide, and there is a need for effective methods for weight loss and weight maintenance to empower individuals to make changes. The purpose of this systematic review was to examine the evidence available for successful diet strategies for weight loss and weight maintenance among adults. A search was conducted of the following databases: CAB Abstracts, Central Register of Controlled Trials, EMBASE, MEDLINE, Food Science and Technology Abstracts, and Web of Knowledge. The studies investigated had participants who were overweight or obese and between 18 and 65 years of age. A successful study was defined as one that reported an intervention that created ≥5% weight loss from baseline and a maintenance phase during which the ≥5% weight loss was maintained from baseline to 12 months. After exclusions, the search resulted in 67 papers. Overall, for significant safe weight loss, an energy deficit was required, which was commonly achieved by reduced fat intake. Increased dietary fibre was also a component of 21% of successful interventions. Physical activity was included in 88% of successful interventions, and behaviour training such as self-monitoring was part of 92% of successful interventions. The same combination of energy and fat restriction, regular physical activity, and behavioural strategies was also required for successful weight maintenance. This review confirmed previous knowledge about weight loss and weight maintenance in adults. A comprehensive approach, including reduced dietary intake, regular physical activity, and behavioural strategies, is warranted and is supported by the research evidence.

Understanding Eating and Exercise Behaviors in Post Roux-en-Y Gastric Bypass Patients: A Quantitative and Qualitative Study

BACKGROUND

Weight regain following gastric bypass (GB) surgery continues to plague many individuals across the United States. However, understanding long-term eating and exercise behaviors to promote and sustain a lower weight following GB surgery is limited.

METHOD

The purpose of this study was to explore the perceptions and attitudes of eating and exercise behaviors associated with weight maintenance in post-GB patients (n=24) 2 or more years postsurgery. Demographic, anthropometric, and food record data were collected. Focus groups and personal interviews were used to understand behaviors and support systems associated with weight stabilization. Focus groups were audio-taped, transcribed, and organized into common themes.

RESULTS

All participants were female, with a mean of 6 years postsurgery, and had a mean age of 51.8±10.5 years. The majority were married (71%) and had a college degree (58%). Although the average weight regain postsurgery was estimated at 16.2±12.7 kg, most of the women (75%) had maintained a significant weight loss of at least 50% of their excess body weight. Themes associated with weight regain emerging from the focus groups included variable family support and a return to "old eating habits."

CONCLUSION

Focus group participants identified lack of long-term emotional support from family members and limited community support for weight loss surgery patients.

Stress management can facilitate weight loss in Greek overweight and obese women: a pilot study

BACKGROUND

Stress and negative emotions have been shown to be critical factors in inducing overeating as a form of maladaptive coping in obese people.

METHODS

The present study aimed to evaluate the efficacy of an 8-week stress management programme that includes progressive muscle relaxation (PMR) and diaphragmatic breathing on weight loss and eating behaviour in a sample of overweight and obese women who started a weight-loss programme. A total of 34 women with a mean (SD) body mass index of 38.17 (7.19) kg m(-) ² and mean (SD) age 47.35 (11.64) years were recruited from the outpatients Obesity Clinic of a public hospital in Athens. Participants were randomly assigned into a Stress Management (SM) and a control group. Anthropometric measurements were taken before and after the intervention, and the participants completed the following questionnaires: Dutch Eating Behaviour Questionnaire (DEBQ), Eating Attitudes Test (Eat-26), Health Locus of Control (HLC) and Perceived Stress Scale (PSS) before and after the intervention.

RESULTS

The findings indicated a significant improvement in weight loss in the SM group [4.44 (0.83) kg] after intervention compared to the control group [1.38 (0.78) kg] (P < 0.05). A higher restrained eating behaviour was observed in the SM group after intervention compared to the control group, although there was no significant difference in perceived stress levels.

CONCLUSIONS

The intervention group showed greater weight reduction, possibly because of the stress management programme, and a greater dietary restraint was demonstrated by them compared to the control group. It is likely that stress management could facilitate weight loss in obese women; however, more studies are needed to confirm this hypothesis.

The dopamine β-hydroxylase inhibitor, nepicastat, suppresses chocolate self-administration and reinstatement of chocolate seeking in rats

Craving for chocolate is a common phenomenon, which may evolve to an addictive-like behaviour and contribute to obesity. Nepicastat is a selective dopamine β-hydroxylase (DBH) inhibitor that suppresses cocaine-primed reinstatement of cocaine seeking in rats. We verified whether nepicastat was able to modify the reinforcing and motivational properties of a chocolate solution and to prevent the reinstatement of chocolate seeking in rats. Nepicastat (25, 50 and 100 mg/kg, intraperitoneal) produced a dose-related inhibition of operant self-administration of the chocolate solution in rats under fixed-ratio 10 (FR10) and progressive-ratio schedules of reinforcement, measures of the reinforcing and motivational properties of the chocolate solution, respectively. The effect of nepicastat on the reinstatement of chocolate seeking was studied in rats in which lever-responding had been extinguished by removing the chocolate solution for approximately 8 d. Nepicastat dose-dependently suppressed the reinstatement of lever-responding triggered by a ‘priming’ of the chocolate solution together with cues previously associated with the availability of the reward. In a separate group of food-restricted rats trained to lever-respond for regular food pellets, nepicastat reduced FR10 lever-responding with the same potency as for the chocolate solution. Spontaneous locomotor activity was not modified by nepicastat doses that reduced self-administration of the chocolate solution and regular food pellets and suppressed the reinstatement of chocolate seeking. The results indicate that nepicastat reduces motivation to food consumption sustained by appetite or palatability. Moreover, the results suggest that DBH inhibitors may be a new class of pharmacological agents potentially useful in the prevention of relapse to food seeking in human dieters.

The defence of body weight: a physiological basis for weight regain after weight loss

Although weight loss can usually be achieved by restricting food intake, the majority of dieters regain weight over the long-term. In the hypothalamus, hormonal signals from the gastrointestinal tract, adipose tissue and other peripheral sites are integrated to influence appetite and energy expenditure. Diet-induced weight loss is accompanied by several physiological changes which encourage weight regain, including alterations in energy expenditure, substrate metabolism and hormone pathways involved in appetite regulation, many of which persist beyond the initial weight loss period. Safe effective long-term strategies to overcome these physiological changes are needed to help facilitate maintenance of weight loss. The present review, which focuses on data from human studies, begins with an outline of body weight regulation to provide the context for the subsequent discussion of short- and long-term physiological changes which accompany diet-induced weight loss.

Low-calorie diet induced weight loss may alter regulatory hormones and contribute to rebound visceral adiposity in obese persons with a family history of type-2 diabetes

PURPOSE

To examine potential detrimental long-term effects of acute diet-induced weight loss on visceral adiposity, insulin resistance, cortisol, and adipokines in obese individuals at risk for type-2 diabetes.

DATA SOURCES

Anthropometric measures (height, weight, waist circumference), self-report instruments, abdominal computed tomography (CT) scan, and blood samples (glucose, insulin, interleukin-6, leptin, adiponectin) were obtained from a convenience sample of 20 participants at baseline, after a 28-day low-calorie diet (800 kcal/day) intervention, and again 6 months later.

CONCLUSIONS

Fifteen of 20 participants completed the 28-day diet intervention and had a mean weight loss of 15 pounds. Comparison between baseline, postdiet, and 6-month data, demonstrated that although participants had significant improvements after the diet, they regained fat mass, particularly in the visceral area.

IMPLICATIONS FOR PRACTICE

Clinicians may need to revise recommendations for using low-calorie diets to achieve weight loss. Diet-induced weight cycling may contribute to dysregulation of metabolism and have long-term detrimental consequences for accumulation of visceral adipose tissue. The likelihood of success is low, with high dropout rates, and those patients who achieve weight loss are very likely to regain it. Thus, the perceived short-term benefits of calorie-restricted diets in this population likely do not outweigh the potential long-term detrimental effects.

Study protocol for the 10 Top Tips (10TT) trial: randomised controlled trial of habit-based advice for weight control in general practice

BACKGROUND

Primary care is the first port of call for advice about weight control. There is hence a need for simple, effective interventions that can be delivered without specialist skills. We have developed such an intervention; the 10 Top Tips (10TT). This intervention was effective with respect to weight loss in a volunteer population, but has yet to be tested in primary care. The aim of this trial is therefore to test the effectiveness of the 10TT intervention in primary care, incorporating clinical outcomes and health economic analyses.

METHODS/DESIGN

The trial is a two-arm, individually-randomised, controlled trial in obese (BMI ≥ 30) adults (n = 520) in primary care, comparing weight loss in patients receiving the 10TT intervention with weight loss in a control group of patients receiving usual care. The intervention is based on habit formation theory, using written materials to take people through a set of simple weight control behaviours with strategies to make them habitual; an approach that could make it more successful than others in establishing long-term behaviour change. Patients will be recruited from 14 General Practices across England. Randomisation will be through telephoning a central randomisation service using a computer-generated list of random numbers. Patients are followed up at 3, 6, 12, 18 and 24 months. The primary outcome is weight loss at 3 months, with assessment by a health professional who is blind to group allocation. Other follow-ups will be un-blinded. We will examine whether weight loss is maintained up to 24 months. We will also assess changes in the automaticity of the 10TT target behaviours and improvement in clinical markers for potential co-morbidities. Finally, we will undertake a full economic evaluation to establish cost-effectiveness in the NHS context.

DISCUSSION

If proven to be effective when delivered through primary care, 10TT could make a highly cost-effective contribution to improvements in population health.

TRIAL REGISTRATION

ISRCTN16347068.

Lifestyle Interventions to Reduce Obesity and Diabetes

The majority of US adults are overweight or obese, which is a primary risk factor for type 2 diabetes and other chronic diseases. Recent advances in behavioral treatment of obesity have produced significant short- and long-term weight losses that reduce the risk of type 2 diabetes and cardiovascular disease. This article reviews key components of effective behavioral treatment interventions, including diet, exercise, and behavioral and psychosocial strategies. The authors review newer treatment modalities that may enhance dissemination (Internet, smartphone) and discuss applications to clinical practice. Practitioners face multiple barriers to effectively delivering lifestyle interventions in today’s health care setting but, nonetheless, remain powerful motivators in helping patients initiate and maintain weight loss efforts that reduce the risk of type 2 diabetes and other chronic diseases.

Effect of fenfluramine on reinstatement of food seeking in female and male rats: implications for the predictive validity of the reinstatement model

RATIONALE AND OBJECTIVES

Relapse to old unhealthy eating habits while dieting is often provoked by stress or acute exposure to palatable foods. We adapted a rat reinstatement model, which is used to study drug relapse, to study mechanisms of relapse to palatable food seeking induced by food-pellet priming (non-contingent exposure to a small amount of food pellets) or injections of yohimbine (an alpha-2 adrenoceptor antagonist that causes stress-like responses in humans and non-humans). Here, we assessed the predictive validity of the food reinstatement model by studying the effects of fenfluramine, a serotonin releaser with known anorectic effects, on reinstatement of food seeking.

METHODS

We trained food-restricted female and male rats to lever-press for 45-mg food pellets (3-h sessions) and first assessed the effect of fenfluramine (0.75, 1.5, and 3.0 mg/kg, i.p.) on food-reinforced responding. Subsequently, we extinguished the food-reinforced responding and tested the effect of fenfluramine (1.5 and 3.0 mg/kg) on reinstatement of food seeking induced by yohimbine injections (2 mg/kg, i.p.) or pellet priming (four non-contingent pellets).

RESULTS

Fenfluramine decreased yohimbine- and pellet-priming-induced reinstatement. As expected, fenfluramine also decreased food-reinforced responding, but a control condition in which we assessed fenfluramine's effect on high-rate operant responding indicated that the drug's effect on reinstatement was not due to performance deficits.

CONCLUSIONS

The present data support the predictive validity of the food reinstatement model and suggest that this model could be used to identify medications for prevention of relapse induced by stress or acute exposure to palatable food during dietary treatments.

Does sustained weight loss reverse the metabolic syndrome?

The prevalence of the metabolic syndrome (MetS) has increased rapidly in North America in recent years. Presently, the MetS is found in 34.3% of the population, and the prevalence is likely to continue to increase in parallel with the obesity epidemic. Losing weight and long-term maintenance of the weight loss are primary targets to beneficially reverse all of the components of the MetS. This paper reviews the clinical and experimental evidence for the reversal of the metabolic complications related to the MetS that follows a sustained weight loss.

Successful Habits of Weight Losers

Despite the availability of the US Dietary Guidelines for Americans, the prevalence of obesity in adults has increased by 200% since 1980. Although few people have lost weight and maintained weight loss long term, some have and are tracked by the National Weight Control Registry. Results from these studies suggest that people attempting to maintain weight loss should (a) eat a low-calorie diet, (b) eat a routine diet, (c) self-monitor food intake and weight, and (d) engage in physical activity.

Physical activity fluctuations and body fat during adolescence

OBJECTIVE

The objective of the study was to test the hypothesis that greater fluctuations in physical activity lead to greater increases in body fat during adolescence.

METHODS

Seven hundred fifty-six adolescents in Montreal, Canada, aged 12-13 years at baseline, completed a 7-d physical activity recall questionnaire every 3 months over 5 years. Body mass index (BMI), waist circumference, and triceps and subscapular skinfold thickness were measured at baseline and at the end of follow-up. Subject-specific linear regressions, expressing physical activity as a function of time, were fitted and physical activity fluctuation scores were obtained by averaging the absolute values of regression residuals. The association between body fat after 5 years and the physical activity fluctuation score was assessed in linear regressions adjusting for baseline body fat, average number of physical activity sessions per week, diet and sociodemographic variables.

RESULTS

Among boys, there were statistically significant positive associations between physical activity fluctuation and BMI (β, 95% confidence interval: 0.12, 0.02-0.21) and triceps skinfold (0.40, 0.17-0.63). The associations with waist circumference or subscapular skinfold were not statistically significant (0.22, -0.04-0.49; 0.13, -0.05-0.32, respectively). In girls, there were statistically significant negative associations between physical activity fluctuation and BMI (-0.12, -0.20 to -0.03), waist circumference (-0.54, -0.91 to -0.17), subscapular skinfold (-0.41, -0.56 to -0.26) and triceps skinfold (-0.22, -0.38 to -0.05).

CONCLUSION

Physical activity fluctuations appear to affect body fat during adolescence. Sex-specific interventions may be needed given that greater physical activity fluctuations seem unfavourable for boys and beneficial for girls.

Behavioural factors related with successful weight loss 15 months post-enrolment in a commercial web-based weight-loss programme

Objective

As further understanding is required of what behavioural factors are associated with long-term weight-loss success, the aim of the present study was to determine the prevalence of successful weight loss 15 months post-enrolment in a commercial web-based weight-loss programme and which behavioural factors were associated with success.

Design

An online survey was completed 15 months post-enrolment in a commercial web-based weight-loss programme to assess weight-related behaviours and current weight. Participants were classified as successful if they had lost ≥5 % of their starting weight after 15 months.

Setting

Commercial users of a web-based weight-loss programme.

Subjects

Participants enrolled in the commercial programme between August 2007 and May 2008. Six hundred and seventy-seven participants completed the survey.

Results

The median (interquartile range) weight change was −2·7 (−8·2, 1·6) % of enrolment weight, with 37 % achieving ≥5 % weight loss. Multivariate logistic regression analysis found success was associated with frequency of weight self-monitoring, higher dietary restraint score, lower emotional eating score, not skipping meals, not keeping snack foods in the house and eating takeaway foods less frequently.

Conclusions

The findings suggest that individuals trying to achieve or maintain ≥5 % weight loss should be advised to regularly weigh themselves, avoid skipping meals or keeping snack foods in the house, limit the frequency of takeaway food consumption, manage emotional eating and strengthen dietary restraint. Strategies to assist individuals make these changes to behaviour should be incorporated within obesity treatments to improve the likelihood of successful weight loss in the long term.

Practices associated with weight loss versus weight-loss maintenance results of a national survey

BACKGROUND

Few studies have examined the weight-control practices that promote weight loss and weight-loss maintenance in the same sample.

PURPOSE

To examine whether the weight control practices associated with weight loss differ from those associated with weight-loss maintenance.

METHODS

Cross-sectional survey of a random sample of 1165 U.S. adults. The adjusted associations of the use of 36 weight-control practices in the past week with success in weight loss (≥10% lost in the past year) and success in weight-loss maintenance (≥10% lost and maintained for ≥1 year) were examined.

RESULTS

Of the 36 practices, only 8 (22%) were associated with both weight loss and weight-loss maintenance. Overall, there was poor agreement (kappa=0.22) between the practices associated with weight loss and/or weight-loss maintenance. For example, those who reported more often following a consistent exercise routine or eating plenty of low-fat sources of protein were 1.97 (95% CI=1.33, 2.94) and 1.76 (95% CI=1.25, 2.50) times more likely, respectively, to report weight-loss maintenance but not weight loss. Alternatively, those who reported more often doing different kinds of exercises or planning meals ahead of time were 2.56 (95% CI=1.44, 4.55) and 1.68 (95% CI=1.03, 2.74) times more likely, respectively, to report weight loss but not weight-loss maintenance.

CONCLUSIONS

Successful weight loss and weight-loss maintenance may require two different sets of practices. Designing interventions with this premise may inform the design of more effective weight-loss maintenance interventions.

What distinguishes weight-loss maintainers from the treatment-seeking obese? Analysis of environmental, behavioral, and psychosocial variables in diverse populations

BACKGROUND

Understanding the factors that influence successful weight control is critical for developing interventions.

PURPOSE

The purpose of the study was to provide a comprehensive understanding of the role of psychosocial, environmental, and behavioral variables in distinguishing weight-loss maintainers (WLM) from treatment-seeking obese (TSO).

METHODS

WLM (n = 167) had lost > or =10% of their maximum body weight, had kept the weight off for > or =5 years, and were now of normal weight. TSO-1 and TSO-2 had a history of dieting and body mass index > or =25. TSO-1 was predominantly Caucasian; TSO-2 was predominantly African-American. Bayesian model averaging was used to identify the variables that distinguished WLM from TSO-1 and TSO-2.

RESULTS

The variables that most consistently discriminated WLM from TSO were more physical activity (ORs = 3.95 and 2.85), more dietary restraint (ORs = 1.63 and 1.41), and less dietary disinhibition (ORs = 0.69 and 0.83). Environmental variables, including the availability of physical activity equipment, TVs, and high-fat foods in the home, also distinguished WLM from TSO.

CONCLUSIONS

Obesity treatment should focus on increasing conscious control over eating, engaging in physical activity, and reducing disinhibition. Changes in the home environment may help facilitate these behavioral changes.

The neuropharmacology of relapse to food seeking: methodology, main findings, and comparison with relapse to drug seeking

Relapse to old, unhealthy eating habits is a major problem in human dietary treatments. The mechanisms underlying this relapse are unknown. Surprisingly, until recently this clinical problem has not been systematically studied in animal models. Here, we review results from recent studies in which a reinstatement model (commonly used to study relapse to abused drugs) was employed to characterize the effect of pharmacological agents on relapse to food seeking induced by either food priming (non-contingent exposure to small amounts of food), cues previously associated with food, or injections of the pharmacological stressor yohimbine. We also address methodological issues related to the use of the reinstatement model to study relapse to food seeking, similarities and differences in mechanisms underlying reinstatement of food seeking versus drug seeking, and the degree to which the reinstatement procedure provides a suitable model for studying relapse in humans. We conclude by discussing implications for medication development and future research. We offer three tentative conclusions: (1)The neuronal mechanisms of food-priming- and cue-induced reinstatement are likely different from those of reinstatement induced by the pharmacological stressor yohimbine. (2)The neuronal mechanisms of reinstatement of food seeking are possibly different from those of ongoing food-reinforced operant responding. (3)The neuronal mechanisms underlying reinstatement of food seeking overlap to some degree with those of reinstatement of drug seeking.

Nutritional treatment of obesity

The focus of this article is nutritional strategies for weight loss. Following a review of general nutritional principles, the evidence behind specific nutritional weight-loss strategies is presented. These strategies include nutritional supplements, nutrient-limited diets, and energy-limited diets. A brief discussion of nutritional considerations relevant to other weight-loss strategies--pharmacologic, surgical, and exercise-based--is included. Specific evidence-based recommendations are presented.