Effects of intentional weight cycling on non-obese young women

Impact of sustained calorie restriction and weight cycling on body composition in high-fat diet-fed male and female C57BL/6J mice

OBJECTIVE

The objective of this study was to investigate body composition changes with weight cycling (WC) among adult C57BL/6J mice with diet-induced obesity.

METHODS

A total of 555 single-housed mice were fed a high-fat diet ad libitum (AL) from 8 to 43 weeks of age. The 200 heaviest mice of each sex were randomized to the following four groups: ever obese (EO, continued AL feeding); obese weight loser (OWL, calorie-restricted); obese weight loser moderate (OWLM, body weight halfway between EO and OWL); and WC (diet restricted to OWL followed by AL refeeding cycles). Body weight and composition data were collected. Linear regression was used to calculate residuals between predicted and observed fat mass. Linear mixed models were used to compare diet groups.

RESULTS

Although weight loss and regain resulted in changes in body weight and composition, fat mass, body weight, and relative body fat were not significantly greater for the WC group compared with the EO group. During long-term calorie restriction, males (but not females) in the OWLM group remained relatively fatter than the EO group.

CONCLUSIONS

WC did not increase body weight or relative fat mass for middle-aged, high-fat diet-fed adult mice. However, long-term moderate calorie restriction resulted in lower body weight but greater "relative" fat in male mice.

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.

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.

The impact of early body-weight variability on long-term weight maintenance: exploratory results from the NoHoW weight-loss maintenance intervention

BACKGROUND

Weight-loss programmes often achieve short-term success though subsequent weight regain is common. The ability to identify predictive factors of regain early in the weight maintenance phase is crucial.

OBJECTIVE

To investigate the associations between short-term weight variability and long-term weight outcomes in individuals engaged in a weight-loss maintenance intervention.

METHODS

The study was a secondary analysis from The NoHoW trial, an 18-month weight maintenance intervention in individuals who recently lost ≥5% body weight. Eligible participants (n = 715, 64% women, BMI = 29.2 (SD 5.0) kg/m², age = 45.8 (SD 11.5) years) provided body-weight data by smart scale (Fitbit Aria 2) over 18 months. Variability in body weight was calculated by linear and non-linear methods over the first 6, 9 and 12 weeks. These estimates were used to predict percentage weight change at 6, 12, and 18 months using both crude and adjusted multiple linear regression models.

RESULTS

Greater non-linear weight variability over the first 6, 9 and 12 weeks was associated with increased subsequent weight in all comparisons; as was greater linear weight variability measured over 12 weeks (up to AdjR² = 4.7%). Following adjustment, 6-week weight variability did not predict weight change in any model, though greater 9-week weight variability by non-linear methods was associated with increased body-weight change at 12 (∆AdjR² = 1.2%) and 18 months (∆AdjR² = 1.3%) and by linear methods at 18 months (∆AdjR² = 1.1%). Greater non-linear weight variability measured over 12 weeks was associated with increased weight at 12 (∆AdjR² = 1.4%) and 18 (∆AdjR² = 2.2%) months; and 12-week linear variability was associated with increased weight at 12 (∆AdjR² = 2.1%) and 18 (∆AdjR² = 3.6%) months.

CONCLUSION

Body-weight variability over the first 9 and 12 weeks of a weight-loss maintenance intervention weakly predicted increased weight at 12 and 18 months. These results suggest a potentially important role in continuously measuring body weight and estimating weight variability.

Effects of multiple cycles of weight loss and regain on the body weight regulatory system in rats

We studied the effects of multiple cycles of weight loss and regain on the defended body weight in rats. Thirty-six male Wistar rats were divided into three weight-matched groups: weight cyclers (n = 18), ad libitum-fed controls (n = 9), and maturity controls (n = 9). Cyclers underwent four rounds of 20% weight loss from 50% caloric restriction, each cycle followed by recovery to stable plateau weight on ad libitum feeding. Controls ate ad libitum. Maturity controls ate ad libitum and then weight cycled the final two rounds to evaluate the effect of age in later cycles. Cyclers' postdiet plateau weight became progressively lower than that of controls. With each weight loss, ghrelin increased, while insulin and leptin decreased; the magnitude of these changes did not differ across cycles. After four rounds, cyclers' weight (504 ± 7 vs. 540 ± 22 g; P < 0.05) and percent body fat (11.7 vs. 15.2%; P < 0.05) were lower than in controls. After a 4-mo follow-up period of ad libitum feeding, cyclers maintained a lower total fat-pad mass versus controls (8.6 ± 0.5 vs. 15.9 ± 3.6 g; P < 0.01) and a lower glucose area-under-the-curve on oral glucose tolerance tests (P < 0.05). Repeated weight-loss cycles exerted positive effects, durably lowering defended levels of body adiposity and improving glucose tolerance.

Short-Term Effects of Healthy Eating Pattern Cycling on Cardiovascular Disease Risk Factors: Pooled Results from Two Randomized Controlled Trials

Adherence to healthy eating patterns (HEPs) is often short-lived and can lead to repetitive attempts of adopting—but not maintaining—HEPs. We assessed effects of adopting, abandoning, and readopting HEPs (HEP cycling) on cardiovascular disease risk factors (CVD-RF). We hypothesized that HEP cycling would improve, worsen, and again improve CVD-RF. Data were retrospectively pooled for secondary analyses from two randomized, crossover, controlled feeding trials (n = 60, 52 ± 2 years, 30.6 ± 0.6 kg/m²) which included two 5–6 week HEP interventions (Dietary Approaches to Stop Hypertension-style or Mediterranean-style) separated by a four-week unrestricted eating period. Ambulatory and fasting blood pressures (BP), fasting serum lipids, lipoproteins, glucose, and insulin were measured before and during the last week of HEP interventions. Fasting systolic BP and total cholesterol decreased (−6 ± 1 mm Hg and −19 ± 3 mg/dL, respectively, p < 0.05), returned to baseline, then decreased again (−5 ± 1 mm Hg and −13 ± 3 mg/dL, respectively, p < 0.05) when adopting, abandoning, and readopting a HEP; magnitude of changes did not differ. Ambulatory and fasting diastolic BP and high-density lipoprotein cholesterol concentrations followed similar patterns; glucose and insulin remained unchanged. Low-density lipoprotein cholesterol concentrations decreased with initial adoption but not readoption (−13 ± 3 and −6 ± 3, respectively, interaction p = 0.020). Healthcare professionals should encourage individuals to consistently consume a HEP for cardiovascular health but also encourage them to try again if a first attempt is unsuccessful or short-lived.

Fatness and Fluctuating Body Weight: Effect on Central Vasculature

Weight Cycling (WC) is a prevalent behavior associated with adverse cardiovascular (CV) health. However, a 2010 review on the effects of WC and blood pressure (BP) determined that there was not enough evidence to draw definitive conclusions. Central BP is the principal predictor of CV risk compared to peripheral BP. The influence that WC may have specifically on central BP is unknown. Cross-sectional observation of self-reported history of WC on measures of CV health was undertaken. Seventy-five women completed a Weight and Lifestyle Inventory questionnaire, which is considered a reliable index of WC (r = 0.87, p < 0.001). Measures of visceral fat, BP, arterial stiffness, and VO2peak were taken. Regression equations were used to assess primary predictors of these outcomes. Seventy-five middle aged (39 ± 11 years), obese (32 ± 7 kg/m2), and relatively unfit (24 ± 8 ml·kg-1 min-1) women completed the study. Visceral fat was the strongest predictor of brachial systolic blood pressure (SBP; r2 = 0.283), brachial diastolic blood pressure (DBP; r2 = 0.176), central SBP (r2 = 0.375), and augmentation index (AIx; r2 = 0.535, all p < 0.001). VO2peak was the strongest predictor of central DBP (r2 = 0.062, p = 0.036) and augmentation pressure (AP; r2 = 0.491, p < 0.001). Weight cycling index was associated with visceral fat (r = 0.521, p < 0.001). Visceral fat was a mediator between WC and central SBP (confidence interval [CI] = 0.0053-0.0602), AP (CI = 0.0507-0.4915), AIx (CI = 0.0025-0.0699), and carotid-femoral pulse wave velocity (CI = 0.0115-0.1227; all p < 0.05). WC may increase visceral fat accumulation, which was associated with increased central SBP and measures of arterial stiffness.

Hypothalamic miR-219 regulates individual metabolic differences in response to diet-induced weight cycling

Consumption of a low calorie diet is the most common approach to lose weight. While generally effective at first, it is frequently followed by a relapse where the pre-diet weight is regained, and often exceeded. This pattern of repeated weight loss/regain is referred to as weight cycling and the resulting metabolic response varies greatly between individuals.

Objective

We attempted to address the issue of individual differences in the response to weight cycling in male mice.

Methods

We first exposed adult wild type mice to repeated cycles of high/low fat food. Next, using a lentiviral approach, we knocked-down or over-expressed miR-219 in the ventromedial hypothalamus (VMH) of an additional mouse cohort and performed a full metabolic assessment.

Results

Exposure of wild type males to weight cycling resulted in the division of the cohort into subsets of resistant versus metabolic-syndrome-prone (MS) animals, which differed in their metabolic profile and hypothalamic miR-219 levels. Lentiviral knock-down of miR-219 in the VMH led to exacerbation of metabolic syndrome. In contrast, over-expression of miR-219 resulted in moderation of the metabolic syndrome phenotype.

Conclusions

Our results suggest a role for miR-219 in the mediation of the metabolic phenotype resulting from repeated weight cycling.

•

Repeated cycles of high fat diet induce different responses in adult males.

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Low miR-219 in ventromedial hypothalamus are linked to metabolic-syndrome proneness.

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Lentiviral knockdown of miR-219 induces metabolic-syndrome-prone phenotype.

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Lentiviral overexpression of miR-219 provides moderate protection from metabolic-syndrome.

Irregular Patterns in the Daily Weight Chart at Night Predict Body Weight Regain

This study examined whether charting daily weight patterns can predict weight regain in obese patients. The subjects were 98 moderately obese Japanese women aged 23 to 66 years who were obliged to precisely record their daily weights during the initial 4-month education period, but not thereafter. The patients were followed up at 8, 12, and 16 months. Abdominal fat areas and blood samples were assessed in the outpatient clinic at 0, 4, and 16 months. The standard deviations (SDs) of the differences in body weight between “after waking up” and “after breakfast” (SDa), “after dinner” (SDb), and “before going to bed” (SDc) were calculated, which were parameters reflecting the fluctuations in the daily weight patterns during the first 4 months. SDc, but not SDa or SDb, was correlated positively with weight regain at 8, 12, and 16 months (P = 0.049, P = 0.002, and P = 0.001, respectively). There were significant differences in temporal change in body weight and abdominal visceral fat between the small SDc group (SDc ≤25th percentile) and the large SDc group (SDc >75th percentile), but not for subcutaneous abdominal fat or the serum concentrations of glucose, insulin, or lipids. The results indicate that fluctuation of body weight immediately before going to bed is useful for predicting the rebound in body weight.

Persistent metabolic adaptation 6 years after "The Biggest Loser" competition

OBJECTIVE

To measure long-term changes in resting metabolic rate (RMR) and body composition in participants of "The Biggest Loser" competition.

METHODS

Body composition was measured by dual energy X-ray absorptiometry, and RMR was determined by indirect calorimetry at baseline, at the end of the 30-week competition and 6 years later. Metabolic adaptation was defined as the residual RMR after adjusting for changes in body composition and age.

RESULTS

Of the 16 "Biggest Loser" competitors originally investigated, 14 participated in this follow-up study. Weight loss at the end of the competition was (mean ± SD) 58.3 ± 24.9 kg (P < 0.0001), and RMR decreased by 610 ± 483 kcal/day (P = 0.0004). After 6 years, 41.0 ± 31.3 kg of the lost weight was regained (P = 0.0002), while RMR was 704 ± 427 kcal/day below baseline (P < 0.0001) and metabolic adaptation was -499 ± 207 kcal/day (P < 0.0001). Weight regain was not significantly correlated with metabolic adaptation at the competition's end (r = -0.1, P = 0.75), but those subjects maintaining greater weight loss at 6 years also experienced greater concurrent metabolic slowing (r = 0.59, P = 0.025).

CONCLUSIONS

Metabolic adaptation persists over time and is likely a proportional, but incomplete, response to contemporaneous efforts to reduce body weight.

Dieting and weight cycling as risk factors for cardiometabolic diseases: who is really at risk?

Despite the poor prognosis of dieting in obesity management, which often results in repeated attempts at weight loss and hence weight cycling, the prevalence of dieting has increased continuously in the past decades in parallel to the steadily increasing prevalence of obesity. However, dieting and weight cycling are not limited to those who are obese or overweight as substantial proportions of the various population groups with normal body weight also attempt to lose weight. These include young and older adults as well as children and adolescents who perceive themselves as too fat (due to media, parental and social pressures), athletes in weight-sensitive competitive sports (i.e. mandatory weight categories, gravitational and aesthetic sports) or among performers for whom a slim image is professionally an advantage. Of particular concern is the emergence of evidence that some of the potentially negative health consequences of repeated dieting and weight cycling are more readily seen in people of normal body weight rather than in those who are overweight or obese. In particular, several metabolic and cardiovascular risk factors associated with weight cycling in normal-weight individuals have been identified from cross-sectional and prospective studies as well as from studies of experimentally induced weight cycling. In addition, findings from studies of experimental weight cycling have reinforced the notion that fluctuations of cardiovascular risk variables (such as blood pressure, heart rate, sympathetic activity, blood glucose, lipids and insulin) with probable repeated overshoots above normal values during periods of weight regain put an additional stress on the cardiovascular system. As the prevalence of diet-induced weight cycling is increasing due to the opposing forces of an 'obesigenic' environment and the media pressure for a slim figure (that even targets children), dieting and weight cycling is likely to become an increasingly serious public health issue.

Effects of a caloric restriction weight loss diet on tryptophan metabolism and inflammatory biomarkers in overweight adults

PURPOSE

Recent data suggest that chronic low-grade inflammation, a characteristic of obesity, is associated with altered tryptophan (Trp) and tyrosine (Tyr) metabolism and plays a role in neuropsychiatric symptoms. The present study assessed the effect of an extreme short-term diet on Trp breakdown and inflammatory biomarkers in overweight adults.

METHODS

Thirty-eight overweight participants (16 women, 22 men; average body mass index: 29 kg/m², mean age 52.8 years) were randomized into two diet groups: a very low kcal diet group (VLCD; Ø 600 kcal/day, n = 21) and a low kcal diet group (LCD; Ø 1,200 kcal/day, n = 17). Assays included the measurement of Trp, kynurenine (Kyn), and their ratio, neopterin, phenylalanine (Phe), Tyr, as biologic markers; leptin, plasma insulin, glucose, and homeostatic model assessment-insulin resistance; and interleukin 6, tumor necrosis factor alpha, and C-reactive protein, as biochemical and inflammatory markers at baseline and after 2 weeks of treatment.

RESULTS

Weight loss diet lowered leptin levels in both groups by 46%, although not reaching significance. Trp and Kyn decreased significantly by 21 and 16% for VLCD and by 15 and 17% for the LCD group, respectively. A significant reduction in Phe was only seen after VLCD. Inflammatory biomarkers, neopterin, and Tyr were not significantly altered during the study period. Leptin was significantly correlated with Trp breakdown before and after the intervention (P < 0.02).

CONCLUSIONS

Since disturbed metabolism of Trp affects biosynthesis of serotonin and might be associated with increased susceptibility for mood disturbances and carbohydrate craving, strategies to supplement Trp while dieting could be highly useful in treating uncontrolled weight gain or in preventing neuropsychiatric symptoms.

Atherosclerosis and cardiac function assessment in low-density lipoprotein receptor-deficient mice undergoing body weight cycling

Background:

Obesity has become an epidemic in many countries and is supporting a billion dollar industry involved in promoting weight loss through diet, exercise and surgical procedures. Because of difficulties in maintaining body weight reduction, a pattern of weight cycling often occurs (so called ‘yo-yo' dieting) that may result in deleterious outcomes to health. There is controversy about cardiovascular benefits of yo-yo dieting, and an animal model is needed to better understand the contributions of major diet and body weight changes on heart and vascular functions. Our purpose is to determine the effects of weight cycling on cardiac function and atherosclerosis development in a mouse model.

Methods:

We used low-density lipoprotein receptor-deficient mice due to their sensitivity to metabolic syndrome and cardiovascular diseases when fed high-fat diets. Alternating ad libitum feeding of high-fat and low-fat (rodent chow) diets was used to instigate weight cycling during a 29-week period. Glucose tolerance and insulin sensitivity tests were done at 22 and 24 weeks, echocardiograms at 25 weeks and atherosclerosis and plasma lipoproteins assessed at 29 weeks.

Results:

Mice subjected to weight cycling showed improvements in glucose homeostasis during the weight loss cycle. Weight-cycled mice showed a reduction in the severity of atherosclerosis as compared with high-fat diet-fed mice. However, atherosclerosis still persisted in weight-cycled mice as compared with mice fed rodent chow. Cardiac function was impaired in weight-cycled mice and matched with that of mice fed only the high-fat diet.

Conclusion:

This model provides an initial structure in which to begin detailed studies of diet, calorie restriction and surgical modifications on energy balance and metabolic diseases. This model also shows differential effects of yo-yo dieting on metabolic syndrome and cardiovascular diseases.

Restrained eating is related to accelerated reaction to high caloric foods and cardiac autonomic dysregulation

Cognitive bias to food-cues and cardiac autonomic dysregulation have both been related to disordered eating behavior in previous research. The present study investigated two possible measures of self-regulatory ability in restrained eaters: resistance to distractor interference and vagal-cardiac control. Young women (N=47) performed a flanker task involving high caloric food-cues or neutral pictures. Vagal-cardiac activity was calculated from baseline heart rate recordings at rest. Restrained eaters did not differ from unrestrained eaters in resistance to distractor interference. However, restrained eaters showed shorter reaction times to high-calorie food-cues as compared to neutral pictures than unrestrained eaters. This attentional bias was further related to low dieting success. Moreover, restrained eating was associated with low parasympathetic activation and sympathovagal imbalance, independent of current body mass. Both attentional bias and cardiac autonomic dysregulation were related to self-reported weight fluctuations. Results are discussed in terms of possible adverse consequences of weight cycling in young women and low self-regulatory ability in restrained eaters.

Weight cycling during growth and beyond as a risk factor for later cardiovascular diseases: the 'repeated overshoot' theory

In people trying to lose weight, there are often repeated cycles of weight loss and regain. Weight cycling is, however, not limited to obese adults but affects people of normal weight, particularly young women, who are unhappy with their appearance. Furthermore, the onset of a pattern of weight cycling is shifting towards younger ages, owing to the increasing prevalence of overweight and obesity in children and adolescents, and the pressure from the media and society for a slim image even for normal weight children. Although there is still controversy whether weight cycling promotes body fat accumulation and obesity, there is mounting evidence from large population studies for increased cardiovascular risks in response to a behavior of weight cycling. Potential mechanisms by which weight cycling contributes to cardiovascular morbidity include hypertension, visceral fat accumulation, changes in adipose tissue fatty acid composition, insulin resistance and dyslipidemia. Moreover, fluctuations in blood pressure, heart rate, sympathetic activity, glomerular filtration rate, blood glucose and lipids that may occur during weight cycling--with overshoots above normal values during weight regain periods--put an additional load on the cardiovascular system, and may be easily overlooked if humans or animals are studied during a state of relatively stable weight. Overshoot of those risks factors, when repeated over time, will stress the cardiovascular system and probably contribute to the overall cardiovascular morbidity of weight cycling.

Changes in C-reactive protein during weight loss and the association with changes in anthropometric variables in men and women: LIFE Study

OBJECTIVE

To investigate whether sex differences exist in the pattern of change in C-reactive protein (CRP) levels during weight loss, and whether the associations between weight change and CRP change differ by the types of anthropometric variables.

DESIGN

Longitudinal, prospective analysis of subjects participating in an intentional weight loss trial (the Lose It For Ever: LIFE Study) followed-up for 30 months.

SUBJECTS

A total of 212 healthy, obese men and women (age: 23-77 years, body mass index (BMI): 30-39 kg m(-2)) took part in this study.

MEASUREMENTS

BMI, waist and hip circumferences, and waist-to-hip ratio, CRP and lifestyle variables repeatedly measured at baseline, 6, 12, 18 and 30-month follow-up.

RESULTS

Weight change was J shaped with a nadir at 12 months in both men and women (P for month(2) <0.0001). CRP level was consistently higher in women than in men, but the differences were less prominent and were not statistically significant at 12- and 18-month follow-up. CRP changes between any two consecutive visits were significantly associated with changes in BMI during the same period in women. However, the associations between CRP changes and changes in waist or hip circumference were not as consistent, especially between 18- and 30-month follow-up when CRP significantly increased. The associations in men were generally similar among the different anthropometric measures. The association between changes in BMI and CRP was stronger in men than in women.

CONCLUSION

BMI change generally correlated well with CRP changes in both men and women in the course of follow-up. Significant sex difference in CRP level at baseline diminished at 12- and 18-month follow-up, when both sexes had maintained the lost weight.

Fitness and weight cycling in relation to body fat and insulin sensitivity in normal-weight young women

A direct link has been established between insulin resistance and obesity; however, the influence of body fat content on insulin sensitivity in normal-weight individuals has not been explored. The aim of this cross-sectional study was to examine differences in insulin sensitivity, glycemic control, and blood lipid levels in normal-weight, healthy participants differing in their body fat. Physical activity, cardiorespiratory fitness, weight cycling, nutrient intake, and eating behavior were also assessed. Two groups of normal-weight (body mass index <25) young, healthy women were recruited: a high-body-fat group with body fat >30% of body weight (n=15) and a low-body-fat group (fat < or =30%, n=17). Data were collected between November 2003 and March 2004. Participants were matched for age and body fat distribution (assessed by the waist-to-hip ratio). The high-body-fat group displayed lower values of insulin sensitivity compared to the low-body-fat group (1/homeostasis model assessment of insulin resistance 1.003+/-0.083 vs 1.385+/-0.158, respectively; P<0.05), whereas no differences were observed on blood lipid levels and glycemic control between groups. High-body-fat participants had lower cardiorespiratory fitness (25.2+/-1.2 vs 28.2+/-1.4 mL/kg/min in the low-body-fat group, P<0.05) and higher incidence of weight cycling of 1.0 to 2.5 kg loss per lifetime (18+/-3 kg vs 8+/-2 kg in the low-body-fat group, P<0.05). The latter variable was the only factor significantly associated with body fat. These data suggest that increased adiposity in normal weight, healthy women may adversely affect insulin sensitivity and that it may be related to differences in physical fitness and eating behavior.

Weight loss and regain and effects on body composition: the Health, Aging, and Body Composition Study

BACKGROUND

Older adults are less able to conserve lean mass relative to fat mass with weight change. A cycle of weight loss and regain in an older individual could accelerate sarcopenia. We examined whether older adults experiencing weight loss and regain would show a greater loss of lean mass during a weight-loss period than gain in lean mass during the weight-regain period, thus have overall a greater net loss of lean mass compared with those who maintained weight in the Health, Aging, and Body Composition Study.

METHODS

We compared the body composition change in 147 older weight changers (54% women, 38% black) with the gender- and race-matched weight-stable individuals over the weight-cycling period. A weight cycle was defined as weight loss of 3% or more with regain of within +/-3% of baseline weight for a period of 2 years.

RESULTS

Both men and women showed significantly lower total body mass after the weight loss and regain. Proportionally, more lean mass was lost during the weight-loss period than was gained during the weight-regain period, especially in men. After weight regain, men showed only a slightly lower lean mass than the stable group, and this was not statistically significant, although the failure to fully regain total weight explained most of the deficit in lean mass after the weight cycle.

CONCLUSION

These data suggest that weight loss even with regain may contribute to a net loss of lean mass in older men but warrant further studies.

Changes and variations of body weight as risk factors for coronary heart disease

Introduction Weight variations are a common phenomenon. Therefore, concern has been raised about the association between weight changes and weight variations and coronary heart disease (CHD). The aim of this study was to estimate the influence of weight change and weight variations as risk factors for coronary heart disease. Materials and methods The investigation was conducted as an observational cross-sectional study, including 102 participants of both genders: 61 patients with CHD and 41 healthy controls. All participants underwent anthropometric measurements and completed a questionnaire that included 1) weight changes in adulthood (maximum and minimum weight), 2) presence and number of weight variations in the 10 years prior to the onset of disease and 3) the size of weight change (weight gain or weight loss in kg). One weight variation was defined as weight loss followed by weight gain for more than 10% of body weight, or about 7 kg. Multivariant logistic regression was used for the estimation of significant predictors for the occurrence of coronary heart disease. Results Participants with CHD had higher values of body weight in adulthood compared to healthy controls, larger number of weight variations in the last 10 years, and more frequently reported weight gain and weight loss for more than 10 kg. The highest risk for the occurrence of coronary heart disease was observed for participants who had more than 3 weight variations for 10% (OR=2.13; 95%CI=0.98-5.48), those with weight loss over 10 kg (OR=2.16; 95%CI=1.71-2.72) and those with weight gain over 10 kg (OR=2.71; 95%CI=1.08-6.83), regardless of gender, age, smoking, body mass index and blood pressure. Discussion Several mechanisms are suggested to explain the relationship between weight changes and variations and coronary heart disease, including changes in plasma lipid levels, insulin levels, decrease of HDL cholesterol, increase of C-reactive protein and increase of blood pressure. Conclusion This study suggests that frequent and very intense weight changes can be considered important predictors for the occurrence of coronary heart disease.

A comparison of body perceptions in relation to measured body composition in young Japanese males and females

The body composition of 139 Japanese females and 84 Japanese males (aged 18-30 years) was measured using anthropometry to assess gender differences in body perceptions in relation to their measured values. Participants were asked to rate perceptions of their own "heaviness" and "fatness" and these were compared to their BMI and percent body fat (%BF). Japanese females showed a significantly greater desire to lose body weight (-4.20+/-0.6 kg) compared to males (0.27+/-1.4 kg). Females also showed poor understanding of their "heaviness" and "fatness" in relation to actual body composition compared to males. The results confirmed distinct gender differences in body perception in relation to actual body composition and attitudes to weight management. Further promotion of "healthy" body image is recommended for the Japanese population.

Effects of leucine and phenylalanine supplementation during intermittent periods of food restriction and refeeding in adult rats

Although many studies have shown that amino acid ingestion acutely stimulates protein anabolism, only few studies have investigated whether long-term supplementation promotes changes in body composition. We therefore tested the hypothesis that l-leucine (LEU) and l-phenylalanine (PHE) supplementation might have a positive impact on the body composition of rats submitted to intermittent periods of food restriction and refeeding (weight cycling or WC). The WC protocol comprised three cycles, each consisting of 1 week of 50% food restriction followed by 2 weeks of ad libitum ingestion. The groups submitted to WC ingested the control diet (WC-CON) or the diet supplemented with LEU+PHE (WC-AA). A pair-fed group receiving the control diet (PF-CON) was used as a reference for the effects of WC. Although food intake was the same in all groups, higher body weight and energy efficiency were observed in the WC-AA group compared to the PF-CON and WC-CON groups although not significantly in relation to the latter. These results were the consequence of a significant increase of lean body mass and body protein content in the WC-AA group compared to the PF-CON and WC-CON groups. The WC-CON and WC-AA groups presented 36.1% and 18.9% more body fat, respectively, than the PF-CON group but this difference was not significant. Neither fasting insulin nor glucose concentration nor postprandial insulin secretion was significantly affected by the supplemented diet. In conclusion, supplementation with LEU+PHE improved the body composition profile of rats submitted to WC, mainly by increasing lean body mass and body protein content.

Predictors of long-term weight maintenance

OBJECTIVE

The purpose of this study was to evaluate available variables of a long-term weight maintenance study to investigate possible factors predisposing to weight regain after a period of weight loss.

RESEARCH METHODS AND PROCEDURES

The Maastricht Weight Maintenance Study is an ongoing longitudinal study of healthy men and women (29 men and 62 women; 18 to 65 years of age; BMI = 30.2 +/- 3.1 kg/m(2)). A variety of parameters were measured before and after a very-low-energy diet and after a follow-up of at least 2 years.

RESULTS

Mean weight loss was 7.9 +/- 3.6 kg, and percent weight regain was 113.8 +/- 98.1%. Percent BMI regain was negatively associated with an increase in dietary restraint (r = -0.47, p < 0.05). Percent weight regain was negatively correlated with baseline resting metabolic rate (r = -0.38, p = 0.01) and baseline fat mass (r = -0.24, p = 0.05) and positively correlated with the magnitude of change in body weight (BW) expressed as maximum amplitude of BW (r = 0.21, p < 0.05). In addition, amplitude of BW was positively correlated with the frequency of dieting (r = 0.57, p < 0.01).

DISCUSSION

The best predictors for weight maintenance after weight loss were an increase in dietary restraint during weight loss, a high baseline resting metabolic rate, a relatively high baseline fat mass favoring a fat-free mass-sparing effect during weight loss, a rather stable BW, and a low frequency of dieting. Therefore, BW maintenance after BW loss seems to be a multifactorial issue, including mechanisms that regulate an individuals' energy expenditure, body composition, and eating behavior in such a way that energy homeostasis is maintained.

Weight cycling of athletes and subsequent weight gain in middleage

OBJECTIVE

To study the effects of repeated cycles of weight loss and regain as young adults on long-term weight development.

DESIGN

A follow-up study with questionnaires in 1985, 1995 and 2001.

SETTING

Finland.

SUBJECTS

A national cohort of 1838 male elite athletes who had represented Finland in major international sport competitions in 1920-1965, including 370 men engaged in sports in which weight-related performance classes are associated with weight cycling (boxers, weight lifters and wrestlers; further called as weight cyclers), and 834 matched control men with no athletic background.

OUTCOME MEASURE

Weight change since the age of 20 years, body mass index (BMI) and prevalence of obesity and overweight.

RESULTS

The weight cyclers gained 5.2 BMI units from age 20 years to their maximum mean weight, which was at age 58.7 years. Corresponding figures for the controls were 4.2 BMI units at 58.5 years and for other athletes 3.3 BMI units at age 62.5 years. The proportion of obese (BMI> or =30 kg/m(2)) subjects was greatest among the weight cyclers both in 1985 and 1995. In 2001, the weight cyclers were more often obese than other athletes, but did not differ from the controls. The odds ratio for the weight cyclers to be obese compared to other athletes in 1985 was 3.18 (95% confidence intervals 2.09-4.83), and compared to the controls 2.0 (1.35-2.96). The enhanced weight gain of the weight cyclers was not accounted for by present health habits (smoking, alcohol use, use of high-fat milk or physical activity) or weight at age 20 years.

CONCLUSIONS

Repeated cycles of weight loss and regain appear to enhance subsequent weight gain and may predispose to obesity. Chronic dieting with weight cycling may be harmful for permanent weight control.

THE ASSOCIATION BETWEEN WEIGHT FLUCTUATION AND MORTALITY: RESULTS FROM A POPULATION-BASED COHORT STUDY

Previous studies evaluating the association between weight fluctuation and mortality are limited and have conflicting results. This study will further evaluate the association between weight fluctuation and mortality in a nationally representative cohort by performing survival analysis of NHANES I and NHANES I Epidemiologic Follow-up Study (n = 8479; weighted sample = 68,200,905). This cohort was followed from 1971 to 1992 and categorized using weight change over five time points into stable non-obese, stable obese, weight gain, weight loss and weight fluctuation groups. All-cause mortality (ACM) and cardiovascular mortality (CM) were evaluated. Respondents with weight fluctuation had higher ACM (HR: 1.83, 95% CI: 1.25-2.69) and CM hazards ratios (HR: 1.86, 95% CI: 1.10-3.15) than the stable non-obese group, even after controlling for pre-existing disease, initial BMI and excluding those in poor health or incapacitated. Increased mortality was also seen in the weight loss group (ACM HR: 3.36, 95% CI: 2.47-4.55), (CM HR 4.22, 95% CI: 2.60-6.84). The stable obese group did not have increased ACM, but did have increased CM prior to the exclusion of those in poor health or incapacitated. (HR: 2.17, 95% CI: 1.10-4.28). Weight fluctuation is associated with a higher risk of all-cause and cardiovascular disease mortality in the US population, even after adjustment for pre-existing disease, initial BMI and the exclusion of those in poor health or incapacitated. Thus, health care providers should promote a commitment to maintaining weight loss to avoid weight fluctuation and consider patients' weight histories when assessing their risk status.

Essverhalten und psychosoziale Belastung von Personen mit hoher und niedriger wahrgenommener Diäthäufigkeit

Zusammenfassung. In der vorliegenden Studie wurden Personen, die angaben, bereits häufig Diäten durchgeführt zu haben, und Personen, die angaben, selten oder noch nie diätiert zu haben, bezüglich ihrer aktuellen Essgewohnheiten und ihrer psychosozialen Belastung verglichen. Die Stichprobe umfasste 48 Männer und 46 Frauen mit einem durchschnittlichen Alter von 28.6 Jahren, die eingeteilt wurden in Personen, die angaben, bereits häufig (mindestens 4-mal; n = 24) vs. selten oder nie (0-3-mal; n = 70) Schlankheitsdiäten durchgeführt zu haben. Die aktuellen Essgewohnheiten beider Gruppen wurden verglichen anhand des “Fragebogens zum Essverhalten“ (FEV) und des “Inventars zum Essverhalten und Gewichtsproblemen“ (IEG). Die psychosoziale Belastung wurde erfasst mit dem “Kurzfragebogen zur aktuellen Beanspruchung“ (KAB) und dem “Trierer Inventar zur Erfassung von chronischem Stress“ (TICS). Personen mit häufigen Diäten in der Vorgeschichte hatten signifikant höhere Werte auf den FEV-Skalen “gezügeltes Essen“, “Störbarkeit des Essverhaltens“ und “erlebte Hungergefühle“. Dieselben Unterschiede fanden sich für die IEG-Skalen “Stärke und Auslösbarkeit des Essverhaltens“, “sozial situative Auslöser für Mehressen“, und “Essen als Mittel gegen emotionale Belastung“. Auf psychosozialer Ebene wiesen Personen, die häufige Diäten berichten, eine höhere aktuelle Beanspruchung auf und zeigten ein höheres Ausmaß an sozialer Überlastung, Überforderung sowie Besorgnisneigung. Die Ergebnisse werden kritisch diskutiert; darüber hinaus werden gesundheitspsychologische Schlussfolgerungen angerissen.

Cognitive eating restraint scores are associated with body fatness but not with other measures of dieting in women

Nearly 50% of women report dieting to lose weight, but the ability of cognitive eating restraint (CER) scores to separate women based on indicators of restricted intake has not been adequately demonstrated. We examined the ability of the CER subscale of the eating inventory to distinguish differences in resting energy expenditure (REE), body composition, cortisol, dietary intake, and physical activity, in a group of women. Subjects (20.4+/-2.3 years) were divided into high (score>9; n=31) and low (score< or =9; n=34) CER groups based on questionnaire responses. Indirect calorimetry was used to measure REE and dual-energy X-ray absorptiometry to measure body composition. Salivary and 24-hour urinary cortisol were measured by bioassays. Food frequency questionnaires and 4-day food records, physical activity recalls, and anthropometric measures were completed. Women in the high CER group possessed more fat mass (p<0.05) and higher body fat percent (p<0.05) and consumed more servings of fruits and vegetables per day (p<0.05) compared to women in the low CER group. Differences in other indicators were not observed between CER groups. Our findings suggest that cognitive restraint and body fatness may not be independent of one another.

Body fat distribution of overweight females with a history of weight cycling

Weight cycling may cause a redistribution of body fat to the upper body fat compartments. We investigated the distribution of subcutaneous adipose tissue (SAT) in 30 overweight women with a history of weight-cycling and age-matched controls (167 normal weight and 97 overweight subjects). Measurements of SAT were performed using an optical device, the Lipometer. The SAT topography describes the thicknesses of SAT layers at 15 anatomically well-defined body sites from neck to calf. The overweight women with a history of weight cycling had significantly thicker SAT layers on the upper body compared to the overweight controls, but even thinner SAT layers on their legs than the normal weight women. An android fat pattern was attributed to overweight females and, even more pronounced, to the weight cyclers. The majority of normal weight women showed a gynoid fat pattern. Using stepwise discriminant analysis, 89.0% of all weight cyclers and overweight controls could be classified correctly into the two groups. These findings show the importance of normal weight maintenance as a health-promoting factor.

Who does not gain weight? Prevalence and predictors of weight maintenance in young women

OBJECTIVE

To investigate the prevalence and predictors of weight maintenance over time in a large sample of young Australian women.

DESIGN

This population study examined baseline and 4 y follow-up data from the cohort of young women participating in the Australian Longitudinal Study on Women's Health.

SUBJECTS

A total of 8726 young women aged 18-23 y at baseline.

MEASURES

Height, weight and body mass index (BMI); physical activity; time spent sitting; selected eating behaviours (eg dieting, disordered eating, takeaway food consumption); cigarette smoking, alcohol consumption; parity; and sociodemographic characteristics.

RESULTS

Only 44% of the women reported their BMI at follow-up to be within 5% of their baseline BMI (maintainers); 41% had gained weight and 15% had lost weight. Weight maintainers were more likely to be in managerial or professional occupations; to have never married; to be currently studying; and not to be mothers. Controlling for sociodemographic factors, weight maintainers were more likely to be in a healthy weight range at baseline, and to report that they spent less time sitting, and consumed less takeaway food, than women who gained weight.

CONCLUSIONS

Fewer than half the young women in this community sample maintained their weight over this 4 y period in their early twenties. Findings of widespread weight gain, particularly among those already overweight, suggest that early adulthood, which is a time of significant life changes for many women, may be an important time for implementing strategies to promote maintenance of healthy weight. Strategies which encourage decreased sitting time and less takeaway food consumption may be effective for encouraging weight maintenance at this life stage.