A longitudinal evaluation of dietary restraint and its relationship to changes in body weight

Weight Goals, Disordered Eating Behaviors, and BMI Trajectories in US Young Adults

BACKGROUND

Community sample data indicate that weight control efforts in young adulthood may have associations with greater increases in body mass index (BMI) over time.

OBJECTIVE

To determine the prospective associations between weight goals and behaviors in young adults and BMI trajectories over 15-year follow-up using a nationally representative sample.

DESIGN

Longitudinal cohort data collected from 2001 to 2018 of the National Longitudinal Study of Adolescent to Adult Health.

PARTICIPANTS

Young adults aged 18-26 years old at baseline stratified by gender and BMI category.

MAIN MEASURES

Predictors: weight goals, any weight loss/maintenance behaviors, dieting, exercise, disordered eating behaviors.

OUTCOMES

BMI at 7- and 15-year follow-up.

KEY RESULTS

Of the 12,155 young adults in the sample (54% female, 32% non-White), 33.2% reported a goal to lose weight, 15.7% to gain weight, and 14.6% to maintain weight. In unadjusted models, all groups have higher mean BMI at 7- and 15-year follow-up. In mixed effect models, goals to lose weight in men with BMI < 18.5 (5.94 kg/m²; 95% CI 2.58, 9.30) and goals to maintain weight in men with BMI ≥ 25 (0.44; 95% CI 0.15, 0.72) were associated with greater BMI increase compared to no weight goal. Engaging in disordered eating behaviors was associated with greater BMI increase in men with BMI < 18.5 (5.91; 2.96, 8.86) and women with 18.5 ≤ BMI < 25 (0.40; 0.16, 0.63). Dieting (- 0.24; - 0.41, - 0.06) and exercise (- 0.31; - 0.45, - 0.17) were associated with lower BMI increase in women with 18.5 ≤ BMI < 25. In women with BMI < 18.5, dieting was associated with greater BMI increase (1.35; 0.33, 2.37).

CONCLUSIONS

Weight control efforts may have variable effects on BMI over time by gender and BMI category. These findings underscore the need to counsel patients on the effectiveness of weight control efforts and long-term weight management.

A systematic review of the methodology used to study weight change among young adults attending college

INTRODUCTION

Young adulthood is a sensitive developmental period that is high-risk for weight gain. Ample research has focused on weight gain among college students; however meta-analyses report <2 kg pooled estimates of weight gain, which is in the range of normal weight fluctuation, and there is disagreement in the literature regarding common predictors of weight gain. These limitations pose a major barrier to targeted obesity prevention efforts. The present study reviewed the literature assessing college weight gain with a focus on three methodological factors that could contribute to variability in the literature: 1) use of an evidence-supported definition of weight gain (>2 kg or ≥3%); 2) weight measurement protocols; and 3) including weight/BMI in analyses of predictors of weight change.

METHODS

Three databases were systematically searched. Studies were included in the review if the primary goal was to determine magnitude of weight change and/or test predictors of weight change during the academic year, and they reported weight at 2+ time points.

RESULTS

A total of 81 studies were included in the review. Most studies (90%; 73/81) did not use an evidence-supported definition of weight gain. Studies that used an evidence-supported definition reported estimates of gain among students who gained weight to be beyond the range of normal weight fluctuation (4.0-7.5 kg), and occurred in a subset (<32%) of participants. Studies that did not use an evidence-supported definition reported weight gain to be 2.0-4.5 kg, and occurred in the majority >50% of students. Most studies that measured height and weight (71%; 42/59) did not use a fasting protocol and the majority (63%; 37/59) did not conduct measurements at the same time of day. A higher percentage of studies that used a standardized measurement protocol reported weight change >2 kg (44% vs 20%). A lower percentage of studies that used a standardized measurement protocol had substantial variability in weight change estimates (50% vs 69%). The majority of studies that tested predictors of weight gain (74%; 42/57) included weight/BMI as a covariate in analyses.

CONCLUSIONS

The body of literature examining weight change among college students suffers from limitations that may have contributed to overestimations in the percent of students who gain weight, and simultaneous underestimations of the magnitude of weight gain among those who gain weight. Weight gain may be limited to approximately 30% of students in a sample, and weight gain among this subset of students may be substantial (>4 kg). Going forward, use of both an evidence-supported weight gain definition and fasting measurement protocol will likely enhance accuracy in characterizing weight gain among college students, as well as improve researchers' ability to detect important predictors of weight gain.

Disordered eating behaviors and cardiometabolic risk among young adults with overweight or obesity

OBJECTIVE

To determine if unhealthy weight control behaviors or binge-eating behaviors among young adults with overweight/obesity are associated with body mass index (BMI) change and cardiometabolic risk at 7-year follow-up.

METHODS

We used longitudinal cohort data from 5,552 young adults with overweight/obesity at baseline (18-24 years) with 7-year follow-up (24-32 years) from the National Longitudinal Study of Adolescent to Adult Health. Baseline predictors were: (a) unhealthy weight control behaviors such as vomiting, fasting, skipping meals, or laxative/diuretic use to lose weight; or (b) binge-eating behaviors. Participants reporting either unhealthy weight control behaviors or binge-eating behaviors were considered to engage in any disordered eating behavior (DEB). Outcomes at 7-year follow-up were BMI change, incident diabetes, incident hypertension, and incident hyperlipidemia.

RESULTS

Young adults with overweight/obesity reporting unhealthy weight control behaviors at baseline had higher BMI and weight at 7-year follow-up than those without unhealthy weight control behaviors. In regression models adjusting for baseline BMI, race/ethnicity, age, and education, unhealthy weight control behaviors were associated with greater change in BMI in both sexes and binge-eating behavior at baseline was associated with greater odds of incident hyperlipidemia (odds ratio 1.90, 95% CI 1.29-2.79) at 7-year follow-up in males.

CONCLUSIONS

The higher risk for increased BMI (in both males and females) and incident hyperlipidemia (in males) over time in young adults with overweight/obesity who engage in DEBs underscores the need to screen for DEBs in this population and provide referrals and tailored interventions as appropriate.

Stress and psychological constructs related to eating behavior are associated with anthropometry and body composition in young adults

BACKGROUND

The transition to college is associated with weight gain, but the relation between eating behavior indicators and anthropometric outcomes during this period remains unclear.

OBJECTIVE

We aimed to evaluate sex differences in stress, emotional eating, tendency to overeat, and restrained eating behavior, and determine whether the psycho-behavioral constructs assessed immediately prior to starting college are associated with anthropometry and adiposity at the start of college, and with first-semester weight gain.

METHODS

A prospective study administered the Three Factor Eating Questionnaire (TFEQ), Satter Eating Competence Inventory, and Perceived Stress Scale (PSS) to 264 participants one month before college. Body composition was assessed via dual energy X-ray absorptiometry (DXA) at the start of college, and anthropometry (weight, height, waist circumference [WC]) was collected at the beginning and end of the first semester. Ordinary least squares regression tested the cross-sectional association of baseline psychological and behavioral scales with baseline DXA and anthropometry, and the longitudinal association with change in anthropometry.

RESULTS

Among 264 participants, 91% (241) had baseline data, and 66% (173) completed follow-up. In sex-adjusted linear regression models, baseline TFEQ disinhibited and emotional (DE; EE) eating sub-scales were positively associated with baseline weight (P = 0.003; DE, P = 0.014; EE), body mass index (BMI, P = 0.002; DE, P = 0.001; EE), WC (P = 0.004; DE, P = 0.006; EE) and DXA fat mass index (P = 0.023; DE, P = 0.014; EE). Baseline PSS was positively associated with subsequent changes in weight and WC among males only (P_interaction = 0.0268 and 0.0017 for weight and WC, respectively).

CONCLUSION

College freshmen with questionnaire scores indicating a greater tendency to overeat in response to external cues and emotions tended to have greater weight, BMI, and WC at the start of college. Males with higher perceived stress at college entrance subsequently gained significantly more weight in the first semester, but no such relation was evident in females.

The Effect of Breakfast Prior to Morning Exercise on Cognitive Performance, Mood and Appetite Later in the Day in Habitually Active Women

Pre-exercise nutritional practices for active females exercising for mood, cognitive and appetite benefits are not well established. Results from an initial field pilot study showed that higher energy intake at breakfast was associated with lower fatigue and higher overall mood and alertness post-exercise (all p < 0.05). In a follow-up, randomised, controlled trial, 24 active women completed three trials in a balanced, cross-over design. At 0815 h participants completed baseline cognitive tasks, mood and appetite visual analogue scales (VAS) and were administered a cereal breakfast (providing 118 or 236 kcal) or no breakfast. After 45 min, they completed a 30 min run at 65% heart rate reserve (HRR). Parameters were re-assessed immediately after exercise, then hourly until lunch (~1240 h), immediately post-lunch and at 1500 and 1900 h via a mobile phone. Breakfast enhanced feelings of relaxation before lunch (p < 0.05, d > 0.40), though breakfast was detrimental for working memory mid-afternoon (p = 0.019, d = 0.37) and mental fatigue and tension later in the day (all p < 0.05, d > 0.038). Breakfast was also beneficial for appetite control before lunch irrespective of size (all p < 0.05, d > 0.43). These data provide information on pre-exercise nutritional practices for active females and suggest that a small breakfast eaten prior to exercise can benefit post-exercise mood and subjective appetite ratings.

Dieting and restrained eating as prospective predictors of weight gain

Research in normal weight individuals paradoxically suggests that measures of attempted eating restriction might represent robust predictors of weight gain. This review examined the extent to which measures of dieting (e.g., self-reported weight loss dieting in the past year) and dietary restraint (e.g., the Cognitive Restraint scale from the Three-Factor Eating Questionnaire) have prospectively predicted weight change. We located and reviewed 25 prospective studies containing 40 relevant comparisons. Studies were limited to those in which participants were non-obese (with a mean BMI between 18.5 and 30) and averaged at least 12 years old. Neither measure predicted future weight loss. Fifteen of the 20 comparisons (75%) that examined measures of dieting significantly predicted future weight gain whereas only 1 of 20 (5%) that examined restrained eating measures did so. Two plausible explanations for these findings are that: (1) dieters and restrained eaters do not differ in terms of an underlying proneness toward weight gain, but restrained eating represents a more effective means of preventing it; and (2) normal weight individuals who diet do so because they are resisting a powerful predisposition toward weight gain which dieting ultimately fails to prevent. Recent dieting in non-obese individuals may be a valuable proxy of susceptibility to weight gain. This easily assessed characteristic could identify individuals for whom obesity prevention interventions would be particularly appropriate.

Dieting Status and Its Relationship to Weight, Dietary Intake, and Physical Activity Changes Over Two Years in a Working Population

The present study prospectively examined changes in dietary intake, physical activity and weight associated with self-reported efforts to lose weight in a cohort of 3671 men and women sampled from the general population. Dieting efforts, dietary intake, physical activity and weight were measured at two points in time, 24 months apart. At baseline, current dieters reported consuming fewer dairy products, sweets, meat, soft drinks and fried potatoes (all p's < .0001), and engaging more frequently in high-intensity physical activity (p < .0001) than those not currently dieting. At follow-up, current dieters reported consuming fewer sweets (p < .0001) and fried potatoes (p < .0008), and engaging more frequently in moderate-intensity physical activity (p < .02) than those not currently dieting. Prospectively, those who initiated weight-loss diets showed the largest decrease in consumption of sweets (p < .0001), soft drinks (p < .0001), and fried potatoes (p < .01), and increase in frequency of high-intensity physical activity (p < .0001) and moderate-intensity physical activity (p < .007). Those initiating weight-loss diets were the only group to lose weight (1 lb.). Those dieting at baseline but not at follow-up gained the most weight (4 lbs.). Self-reports of current dieting correspond to reported changes in dietary intake and physical activity, and to measured changes in weight over the same time period. Individuals who report dieting to lose weight have healthier eating and exercise patterns than those who do not report dieting.

Stability and change in patterns of concerns related to eating, weight, and shape in young adult women: a latent transition analysis

Although college women are known to be at high risk for eating-related problems, relatively little is known about how various aspects of concerns related to eating, weight, and shape are patterned syndromally in this population. Moreover, the extent to which various patterns represent stable conditions or transitory states during this dynamic period of development is unclear. The present study used latent class and latent transition analysis (LCA/LTA) to derive syndromes of concerns related to eating, weight, and shape and movement across these syndromes in a sample of 1,498 women ascertained as first-time freshmen and studied over 4 years. LCA identified 5 classes characterized by (a) no obvious pathological eating-related concerns (prevalence: 28%-34%); (b) a high likelihood of limiting attempts (prevalence: 29%-34%); (c) a high likelihood of overeating and binge eating (prevalence: 14%-18%); (d) a high likelihood of limiting attempts and overeating or binge eating (prevalence: 14%-17%); and (e) pervasive bulimic like concerns (prevalence: 6%-7%). Membership in each latent class tended to be stable over time. When movement occurred, it tended to be to a less severe class. These findings indicate that there are distinct, prevalent, and relatively stable forms of eating-related concerns in college women.

Sex-based differences in the behavioral and neuronal responses to food

Sex-based differences in food intake related behaviors have been observed previously. The objective of this study was to examine sex-based differences in the behavioral and neuronal responses to food. 22 women and 21 men were studied. After 6 days of controlled eucaloric feeding, ad libitum energy intake (EI) was measured for 3 days. Appetite ratings using visual analog scales were obtained before and after each meal. Functional magnetic resonance imaging was performed in the overnight fasted state on the last day of eucaloric feeding while subjects were presented visual stimuli of food and neutral non-food objects. While hunger and prospective consumption were not different between sexes, women had higher post-meal satiety ratings and dietary restraint than men. Images of hedonic foods resulted in significantly greater activation of lateral and dorsolateral prefrontal cortex (DLPFC) and parietal cortex in women as compared to men. No brain regions were more activated in men as compared to women. Men increased their EI during the ad libitum diet phase. While measures of appetite or feeding behaviors did not correlate with either neuronal activation or subsequent EI, DLPFC activation in response to hedonic foods was negatively correlated with EI. In summary, greater prefrontal neuronal responses to food cues in women may suggest increased cognitive processing related to executive function, such as planning, guidance or evaluation of behavior. Finally, increased DLPFC activation, perhaps relating to inhibitory cognitive control in response to food cues may be a better predictor of food intake than behavioral measures.

Restrained Eating and Risk of Gaining Weight and Body Fat in Middle-Aged Women: A 3-Year Prospective Study

Purpose.

Examine the extent to which restrained eating (RE) and changes in RE influence the risk of weight and fat gain over 36 months in women.

Design.

Prospective cohort.

Setting.

Several communities.

Subjects.

Baseline and follow-up assessments were completed by 192 middle-aged women (ages 40.0 ± 3 years).

Measures.

Body weight was measured with an electronic scale, body fat (BF) was assessed using the Bod Pod, energy intake was evaluated using 7–day weighed food records, physical activity was measured objectively using accelerometers, and RE was indexed using the Dutch Eating Behavior Questionnaire.

Analysis.

Relative risk (RR) was calculated using incidence data.

Results.

The risk of weight gain (> 1 kg) over the 36 months was 69% greater in women who did not increase in RE compared with their counterparts (RR = 1.69, 95% confidence interval [CI] = 1.12–2.52). The risk of substantial weight gain (≥3 kg) was 138% greater in women who did not increase in RE compared with women who did (RR = 2.38, 95% CI = 1.16–4.89), and the risk of gains in BF (≥ 1% point) was 49%) greater (RR = 1.49, 95% CI = 1.02–2.17). Control of potential confounding factors, except changes in energy intake, had little influence on risk.

Conclusion.

Women who do not become more restrained in their eating over time are at much greater risk of gaining weight and BF compared with those who become more restrained.

Dietary restraint and gestational weight gain

OBJECTIVE

To determine whether a history of preconceptional dieting and restrained eating was related to higher weight gains in pregnancy.

DESIGN

Dieting practices were assessed among a prospective cohort of pregnant women using the Revised Restraint Scale. Women were classified on three separate subscales as restrained eaters, dieters, and weight cyclers.

SUBJECTS

Participants included 1,223 women in the Pregnancy, Infection, and Nutrition Study.

MAIN OUTCOME MEASURES

Total gestational weight gain and adequacy of weight gain (ratio of observed/expected weight gain based on Institute of Medicine recommendations).

STATISTICAL ANALYSES PERFORMED

Multiple linear regression was used to model the two weight-gain outcomes, while controlling for potential confounders including physical activity and weight-gain attitudes.

RESULTS

There was a positive association between each subscale and total weight gain, as well as adequacy of weight gain. Women classified as cyclers gained an average of 2 kg more than noncyclers and showed higher observed/expected ratios by 0.2 units. Among restrained eaters and dieters, there was a differential effect by body mass index. With the exception of underweight women, all other weight status women with a history of dieting or restrained eating gained more weight during pregnancy and had higher adequacy of weight gain ratios. In contrast, underweight women with a history of restrained eating behaviors gained less weight compared to underweight women without those behaviors.

CONCLUSIONS

Restrained eating behaviors were associated with weight gains above the Institute of Medicine's recommendations for normal, overweight, and obese women, and weight gains below the recommendations for underweight women. Excessive gestational weight gain is of concern because of its association with postpartum weight retention. The dietary restraint tool is useful for identifying women who would benefit from nutritional counseling prior to or during pregnancy with regard to achieving targeted weight-gain recommendations.

A Scenario-Based Dieting Self-Efficacy Scale

The article discusses a scenario-based dieting self-efficacy scale, the DIET-SE, developed from dieter's inventory of eating temptations (DIET). The DIET-SE consists of items that describe scenarios of eating temptations for a range of dieting situations, including high-caloric food temptations. Four studies assessed the psychometric properties of the 11-item DIET-SE. Exploratory factor analysis ( N = 392) and confirmatory factors analysis ( N = 124) revealed three internally consistent and reliable factors representing challenges to adhere to a diet (high-caloric food temptations [HCF], social and internal factors [SIF], negative emotional events [NEE]). Convergent validity is established with other measures of dieting self-efficacy, as well as measures of eating disinhibition, susceptibility to hunger, and weight loss competency. Criterion-related validity is provided through the assessment of goal adherence, and predictive validity is established for dieters' actual food intake ( N = 68). The DIET-SE represents a short, reliable, and valid scenario-based measure of dieting self-efficacy.

A prospective study of predictors of successful weight maintenance by women enrolled in community-based weight-loss programs

OBJECTIVE

Research is limited on the psychological predictors of successful long-term weight maintenance after weight loss. Therefore, the present study examined the individual contributions of body image, depression, and self-esteem to successful weight maintenance after a significant weight loss.

METHOD

Measures of depression, self-esteem, and body image were administered at baseline, three-, and twelve-months to 73 women enrolled in community- based weight loss programs.

RESULTS

Significant predictors of weight maintenance included baseline self-classified weight, early (3 months) weight maintenance, later (12 months) change in perceptual body image, and the interaction between early and late change in body image avoidance. Classifying oneself as more overweight at baseline predicted less weight maintenance, while later discrepancies between current and realistic body size were positively associated with weight maintenance. Those who showed steady improvements in body image avoidance behavior were more likely to maintain weight loss. Baseline BMI, self-esteem, and depression did not predict 12-month weight maintenance.

DISCUSSION

Further understanding how body image and related factors contribute to weight maintenance may inform development of more effective interventions to promote long-term weight maintenance.

Experimental investigation of the effects of naturalistic dieting on bulimic symptoms: Moderating effects of depressive symptoms

Prospective studies suggest that dieting increases risk for bulimic symptoms, but experimental trials indicate dieting reduces bulimic symptoms. However, these experiments may be unrepresentative of real-world weight loss dieting. In addition, the fact that most dieters do not develop eating disorders suggests moderating factors may be important. Accordingly, we randomly assigned 157 female intermittent dieters to either diet as they usually do for weight loss or eat as they normally do when not dieting for 4 weeks. Naturalistic dieting halted the weight gain shown by controls, but did not result in significant weight loss. Although there was no main effect of the dieting manipulation on bulimic symptoms, moderation analyses indicated that naturalistic dieting decreased bulimic symptoms among participants with initially low depressive symptoms. Results suggest that self-initiated weight loss dieting is not particularly effective, which appears to explain several discrepancies in the literature. Additionally, depressive symptoms may be an important determinant of bulimic symptoms that eclipses the effects of naturalistic dieting on this outcome.

Stress and weight change in university students in the United Kingdom

Students in the US have been shown to gain weight during their first year at university. This study examined whether students in Britain have a similar weight change during their first year at university, and tested the hypothesis that stress plays a role. A cross-sectional survey was conducted to assess stress and perceived weight change. Two hundred and sixty eight students at University College London completed the questionnaire at the end of their first year of university. On average, students reported a significant weight increase (1.53 kg+/-2.70, p<0.001), although there was considerable variation, with 55% of the sample reporting weight gain, 12% weight loss, and 33% remaining stable. Logistic regression analyses demonstrated that stress was associated with greater risk of weight gain (OR, 1.27, 95% CI, 1.12 to 1.44, p=0.001) and weight loss (1.33, 1.10 to 1.61, p=0.003), but associations were stronger among women. The associations remained unchanged after adjustment for health behaviours. Our findings confirm a modest weight gain over the first year at university, which was associated with higher levels of perceived stress in women.

The relationship between restrained eating and poor psychological health is moderated by pleasure normally associated with eating

This study investigated the relationship between restrained eating and poor psychological health, and the importance of pleasure normally associated with eating in this relationship. Pleasure normally associated with eating, restrained eating, and anxiety, depression and satisfaction with life were assessed concurrently by questionnaire. A relationship between restrained eating and poor psychological health was found--greater restrained eating was significantly independently associated with greater anxiety (B=1.099, p<0.01). Furthermore, pleasure associated with eating was an important moderator in this relationship--greater pleasure associated with eating combined with greater restrained eating was also significantly independently associated with greater anxiety (B=1.067, p=0.02). No effects were found for depression or satisfaction with life. These findings suggest that the pleasure normally associated with eating is important in the relationship between restrained eating and poor psychological health. Subsidiary exploratory analyses also suggest that the relationship between restrained eating and poor psychological health, and the importance of pleasure in that relationship, may differ in males and females.

Obesity, Disordered Eating, and Eating Disorders in a Longitudinal Study of Adolescents: How Do Dieters Fare 5 Years Later?

OBJECTIVE

To determine if adolescents who report dieting and different weight-control behaviors are at increased or decreased risk for gains in body mass index, overweight status, binge eating, extreme weight-control behaviors, and eating disorders 5 years later.

DESIGN

Population-based 5-year longitudinal study.

PARTICIPANTS

Adolescents (N=2,516) from diverse ethnic and socioeconomic backgrounds who completed Project EAT (Eating Among Teens) surveys in 1999 (Time 1) and 2004 (Time 2).

MAIN OUTCOME MEASURES

Weight status, binge eating, extreme weight control, and self-reported eating disorder.

STATISTICAL ANALYSIS

Multiple linear and logistic regressions.

RESULTS

Adolescents using unhealthful weight-control behaviors at Time 1 increased their body mass index by about 1 unit more than adolescents not using any weight-control behaviors and were at approximately three times greater risk for being overweight at Time 2 (odds ratio [OR]=2.7 for girls; OR=3.2 for boys). Adolescents using unhealthful weight-control behaviors were also at increased risk for binge eating with loss of control (OR=6.4 for girls; OR=5.9 for boys) and for extreme weight-control behaviors such as self-induced vomiting and use of diet pills, laxatives, and diuretics (OR=2.5 for girls; OR=4.8 for boys) 5 years later, compared with adolescents not using any weight-control behaviors.

CONCLUSIONS

Dieting and unhealthful weight-control behaviors predict outcomes related to obesity and eating disorders 5 years later. A shift away from dieting and drastic weight-control measures toward the long-term implementation of healthful eating and physical activity behaviors is needed to prevent obesity and eating disorders in adolescents.

Influence of heredity on dietary restraint, disinhibition, and perceived hunger in humans

OBJECTIVE

Dietary restraint, disinhibition, and perceived hunger have been shown to affect food intake and body weight and are thought to be risk factors for eating disorders, but little is known about their origins. We investigated the influence of heredity, shared (familial) environment, and individual environment on dietary restraint disinhibition, perceived hunger and their relation to body size and food intake.

METHODS

Scores on the Three Factor Eating Questionnaire and the Restraint Scale in addition to height, weight, body mass index, and 7-d diary reported nutrient intakes were obtained from 39 identical, 60 fraternal same-sex, and 50 fraternal opposite-sex adult twin pairs who were living independently. Linear structural modeling was applied to investigate the nature and degree of genetic and environmental influences.

RESULTS

Analysis showed significant genetic and individual environmental, but not shared (familial) environmental, influences on cognitive restraint, perceived hunger, and Restraint Scale scores, with genes accounting for 44%, 24%, and 58% of the variance, respectively. In contrast, disinhibition was found to be significantly influenced by the shared (familial) environment, accounting for 40% of the variance. Further analysis showed that cognitive restraint and perceived hunger heritabilities could not be accounted for by significant heritabilities of body weight, height, or body mass index. In contrast, the heritability of Restraint Scale scores was found to be related to body size. Cognitive restraint was negatively correlated with nutrient intake, and differences in cognitive restraint were found to be related to differences in the body sizes of identical twin pairs.

CONCLUSIONS

Dietary restraint appears to be another component in a package of genetically determined physiologic, sociocultural, and psychological processes that regulate energy balance, whereas dietary disinhibition may be the intermediary between upbringing and the development of overweight and/or eating disorders.

Effects of priming thoughts about control on anxiety and food intake as moderated by dietary restraint

The study was designed to examine: (a) if activating thoughts about control affects anxiety and food intake and (b) if those effects are moderated by dietary restraint. Eighty female undergraduates were administered the Dietary Restraint questionnaire and were primed for cognitions of control or of lack of control. The participants' perceptions of control over food consumption, their state anxiety, and their food intake as part of an alleged taste-test, were assessed. As evidence for the effectiveness of priming, participants reported less control over food consumption after being primed for lack of control than for control cognitions. As expected, Restraint score was negatively correlated with perceived control over food consumption. Consistent with hypothesis, participants high in dietary restraint experienced greater anxiety after being primed for control than after priming for lack of control, whereas participants low in dietary restraint displayed the opposite pattern. These findings were consistent with the cognitive dissonance principle that individuals experience greater anxiety when cognitions are inconsistent with personal beliefs than when they are consistent. As expected, priming thoughts of lack of control resulted in greater food intake than did priming thoughts of control, supporting the hypothesis of a nonconscious, automatic link between cognitions and food intake.

The effects of modeling dietary restraint on food consumption: do restrained models promote restrained eating?

Sixty-nine female undergraduates completed the restraint scale, a dieting checklist, and the Eating Attribution Style Questionnaire (EASQ). The participants were exposed either to no model, a peer model who behaviorally demonstrated dietary restraint, or a peer model who behaviorally and verbally demonstrated dietary restraint. The participants had an opportunity to consume food as part of a taste test. The findings revealed that attribution style, but not restraint or current dieting status, moderated the effects of exposure to the peer models. Females who had an internal attribution style for indulgent food consumption decreased their consumption of food as a function of the dietary restraint of the models, whereas females who had an external attribution style for indulgent food consumption increased their consumption of food as a function of the dietary restraint of the models. The latter disinhibitory effect was attributed to negative social comparison and learned helplessness. The results supported the conclusion that the effectiveness of modeling dietary restraint is dependent on the attribution style of the observers.

Does dieting make you fat?

Dieting Makes You Fat, the title of a 1980s book on weight control, is a popularised paradox, conveying a conclusion that is consistent with personal experience and the reported failure of most dietary approaches in the treatment of obesity. Few studies have been designed specifically to test this association. Yet there are prospective data showing that baseline dieting or dietary restraint increases the risk of weight gain, especially in women. Metabolic adaptations and the disinhibited eating of restrained eaters have been the most commonly cited explanations for such weight gain. Dietary restraint has also been implicated in the development and persistence of binge eating. The present paper critically evaluates the evidence supporting this paradox and reaches a rather different conclusion.

Dietary restraint and self-esteem as predictors of weight gain over an 8-year time period

The study aimed to assess dietary restraint and self-esteem as predictors of weight change over a time period of 8 years. Questionnaires assessing self-reported weight, body dissatisfaction, dietary restraint, and self-esteem were completed by 77 young adults (19 men and 58 women) on two occasions separated by 8 years. On average, participants gained approximately 6 kg over the 8 years. Although neither dietary restraint nor self-esteem predicted weight change on its own, their interaction did. Furthermore, the relationship between restraint and weight change was best described as curvilinear. It was concluded that dietary restraint is predictive of subsequent weight gain, but in a more complex way than previously assumed.

Weight change among self-reported dieters and non-dieters in white and African American men and women

Few studies have examined the association between dieting and weight change in general population and results have been inconsistent. To the best of our knowledge, no such study has been done in middle-aged African Americans. We examined 10,554 white and African American men and women who were participants in the Atherosclerosis Risk in Communities (ARIC) Study and attended examinations between 1986 and 1994. We found that the prevalence of dieting in white women, white men, African American women, and African American men was 6.5, 2.3, 3.5, and 0.9%, respectively. After controlling for the covariates, the difference in the mean annual weight gain between dieters and nondieters was 0.61, 0.46, and 0.59 kg/year among white women, white men, and African American women, respectively. In conclusion, in this cohort of white men and women and African American women aged 45-64 years, self-reported dieting was associated with a larger mean annual weight gain than non-dieting over a period of 6 years.

Evaluating a 'non-diet' wellness intervention for improvement of metabolic fitness, psychological well-being and eating and activity behaviors

CONTEXT

Current public health policy recommends weight loss for obese individuals, and encourages energy-restricted diets. Others advocate an alternative, 'non-diet' approach which emphasizes eating in response to physiological cues (eg hunger and satiety) and enhancing body acceptance.

OBJECTIVE

To evaluate the effects of a 'health-centered' non-diet wellness program, and to compare this program to a traditional 'weight loss-centered' diet program.

DESIGN

Six-month, randomized clinical trial.

SETTING

Free-living, general community.

PARTICIPANTS

Obese, Caucasian, female, chronic dieters, ages 30-45 y (n=78).

INTERVENTIONS

Six months of weekly group intervention in a non-diet wellness program or a traditional diet program, followed by 6 months of monthly after-care group support.

OUTCOME MEASURES

Anthropometry (weight, body mass index); metabolic fitness (blood pressure, blood lipids); energy expenditure; eating behavior (restraint, eating disorder pathology); psychology (self-esteem, depression, body image); attrition and attendance; and participant evaluations of treatment helpfulness. Measures obtained at baseline, 3 months, 6 months and 1 y.

RESULTS

(1 y after program initiation): Cognitive restraint increased in the diet group and decreased in the non-diet group. Both groups demonstrated significant improvement in many metabolic fitness, psychological and eating behavior variables. There was high attrition in the diet group (41%), compared to 8% in the non-diet group. Weight significantly decreased in the diet group (5.9+/-6.3 kg) while there was no significant change in the non-diet group (-0.1+/-4.8 kg).

CONCLUSIONS

Over a 1 y period, a diet approach results in weight loss for those who complete the intervention, while a non-diet approach does not. However, a non-diet approach can produce similar improvements in metabolic fitness, psychology and eating behavior, while at the same time effectively minimizing the attrition common in diet programs.

Underreporting of energy intake in repeated 24-hour recalls related to gender, age, weight status, day of interview, educational level, reported food intake, smoking habits and area of living

OBJECTIVE

The aims of the present study were (1) to evaluate the degree to which underreporting of energy intake by repeated 24-hour recalls was related to gender, age, weight status, day of interview, educational level, smoking habits and area of living, and (2) to compare the dietary characteristics of underreporters with those of others.

DESIGN

Cross-sectional study. Ten 24-hour recalls were performed during a one-year period.

SETTING

The Västerbotten intervention programme of cardiovascular disease and diabetes in Northern Sweden.

SUBJECTS

Ninety-four men and 99 women in four age groups: 30, 40, 50 and 60 years.

RESULTS

The prevalence of men and women with a food intake level (FIL; reported energy intake divided by estimated basal metabolic rate) below 1.2 was 44% and 47%, respectively. The youngest age group had higher FIL values than the oldest age group for both men (1.5 versus 1.1) and women (1.4 versus 1.1). The prevalence and magnitude of underreporting were directly related to body mass index (BMI; correlation coefficient: -0.47 (men) and -0.55 (women)). Smokers had a lower FIL value (1.1) than non-smokers (1.3). The nutrient density was lower for the group with high FIL values for protein and calcium and higher for fat and sucrose. The upper FIL group often had higher intake frequencies and larger portion sizes than the lower FIL group.

CONCLUSIONS

Underreporting of energy intake is prevalent when 24-hour recalls are used, but the prevalence differs between sub-groups in the population. BMI was the main predictor of underreporting but also old age and smoking seem to contribute in this aspect. Socially desirable food items were not underreported to the same extent as socially undesirable food items. The intake frequencies and portion sizes partly explained the differences in FIL.

Body image and personality predictors of eating disorder symptoms during the college years

OBJECTIVE

Women entering college (N = 118) were longitudinally followed for 3 years with assessments of eating pathology (Restraint and Bulimia).

METHOD

Measures taken at Time 1 included timing of onset of puberty, Figure Dissatisfaction, Ineffectiveness, Public Self-Consciousness, and mood states (Profile of Mood States). Measures were evaluated as predictors of changes in Restraint and Bulimia scores across the three-year period.

RESULTS

Both Restraint (r = .69) and Bulimia (r = .50) were quite stable across the 3 years. Mean weight gain of 5.4 pounds (p < .001) was paralleled by an increase in "ideal weight" of 4.7 pounds. Hierarchical regressions controlling for Time 1 levels of eating disorder symptoms revealed that changes in Bulimia (R(2) = .38, p < .0001) were related to the psychological measures and to Figure Dissatisfaction. Changes in Restraint (R(2) = .61, p < .0001) were significantly related to Figure Dissatisfaction.

DISCUSSION

Findings are discussed in the context of the value of longitudinal designs in identifying risk factors. Dissatisfaction with one's figure seems to be consistently related to worsening eating pathology.

Disordered eating in college freshman women: a prospective study

The authors assessed eating behaviors and attitudes of 225 college freshman women on the bulimia and restraint scales at the beginning of the year. Seven months later, they reassessed 104 of the original students. Concurrent data regression analyses found that symptoms of eating pathology were associated with figure dissatisfaction, ineffectiveness, public self-consciousness, and vigor on the Profile of Mood States, and for bulimia, self-efficacy to control eating when experiencing negative feelings, and reward conditions. Both bulimia and restraint were highly stable across the 7 months. Prospective analyses, controlling for the initial level of eating pathology in hierarchical regressions, found that figure dissatisfaction, ineffectiveness, and alcohol use/abuse over the past year were significant predictors of worsening symptoms. Beginning levels of bulimia and restraint were the best predictors of eating pathology at the end of the study. The roles that self-image and alcohol use may play as vulnerabilities for eating pathology are also considered.

Population-based prevention of eating disorders: an application of the Rose prevention model

BACKGROUND

Several decades of concerted research on eating disorders have generated a broad range of proposed causal influences, but much of this etiologic research does not elucidate practical avenues for preventive interventions. Translating etiologic theory into community health interventions depends on the identification of key leverage points, factors that are amenable to public health intervention and provide an opportunity to maximize impact on the outcome of interest. Population-based preventive strategies, elaborated by epidemiologist Geoffrey Rose, can maximize the impact of public health interventions. In the case of eating disorders, Rose's model is instructive: Dieting stands out as risk behavior that may both fit Rose's model well and be a key leverage point for preventive intervention.

METHODS

Grounded in Rose's work, this article lodges a theoretical argument for the population-based prevention of eating disorders. In the introductory section, existing research on the epidemiology of dieting is reviewed, showing that it is extremely common among adolescent girls and women and that the behavior has been implicated as a causal factor for disordered eating. Next, new evidence is offered to build a case for how a population-wide reduction in dieting may be an effective strategy for prevention of eating pathology. Finally Rose's prevention framework is used to introduce a unique and provocative perspective on the prevention of eating disorders.

RESULTS

Dieting is a normative behavior in our culture with psychological and physiological effects in the causal chain leading to eating pathology. This behavior may represent an ideal target for population-based prevention.

CONCLUSIONS

Theoretical and empirical evidence suggests that a population-wide reduction in dieting may be a justifiable and effective strategy for prevention of eating pathology.

Eating disorders, dieting, and the accuracy of self-reported weight

OBJECTIVE

This study investigated the accuracy of self-reported weight and height in individuals with an eating disorder (i.e., anorexia nervosa [AN] and bulimia nervosa [BN]) and in individuals without an eating disorder (i.e., dieters and nondieters).

METHOD

Self-reported and measured weights and heights were obtained from the eating disorder sample (n = 81) and the college student sample (n = 163) and were compared within and between the groups.

RESULTS

Eating disorder patients were extremely accurate at self-reporting their weight. However, there was a significant difference in accuracy between AN and BN patients. AN patients slightly overreported their weight, whereas BN patients slightly underreported their weight. Both dieters and nondieters significantly underreported their weight. However, dieters significantly underreported their weight to a greater degree than did the nondieters.

DISCUSSION

The implications of these subgroup differences and their specificity to weight reporting are discussed with reference to the accuracy of self-reported height.

Dietary restraint, attributional styles for eating, and preloading effects

A total of 319 undergraduates completed the Restraint Scale and an Eating Attributional Style Questionnaire (EASQ). Subsequently, 101 female students participated in the classic preloading experiment. The results indicated that restrained eating was associated with an external locus of control attribution style, particularly for indulgent food consumption (ELCifc). Partial preloading effects for Restraint were found: The amount consumed increased as a function of Restraint in the preload condition. A more complete pattern of preloading was found for the ELCifc attribution style. In addition, the relationship between Restraint and food consumed in the preload condition was no longer significant with the ELCifc attribution style partialled out. The findings supported the hypotheses that: (a) restrained eaters display an external attribution style of learned helplessness and (b) related cognitions serve as a cause of preloading effects.

Loneliness, dysphoria, dietary restraint, and eating behavior

The study was designed to examine Herman and Polivy's restrained eating theory (Journal of Abnormal Psychology, 84, 666-672, 1975) using two different methods: situational-experimental and dispositional-correlational. Fifty-eight female college students were administered the revised UCLA Loneliness Scale, the Beck Depression Inventory (Short Form), and the Restraint scale. Subsequently, the students were subjected to either a neutral, sad, or loneliness mood induction and then ate cookies under the pretext of participating in a taste test. Consistent with expectation, dieters tended to consume more food in the loneliness than neutral mood condition, whereas nondieters displayed the opposite pattern. A comparable pattern was found in the relation between the revised UCLA Loneliness Scale and food consumption with respect to Restraint; the amount of food consumed increased as a function of loneliness for high restrained eaters, whereas the amount of food consumed decreased as a function of loneliness for low restrained eaters. There were no appreciable effects of the sad mood induction, nor prediction by dispositional depression, regarding the amount of food consumed as a function of dietary restraint. The findings were discussed with respect to the motivational role that loneliness may play in inhibiting and disinhibiting food consumption.

Dietary restraint as a predictor of reported weight loss and affect

This study investigated dietary restraint as a predictor of subsequent reported weight loss. Neither chronic dieters nor nondieters reported actually losing weight over a 7-mo. period. With respect to recent weight change, restrained eaters reported both more recent weight loss and more recent weight gain than unrestrained eaters. Further, such weight changes had a much larger influence on their affect. It was concluded that chronic dieting is likely to produce temporary swings in both weight and mood but no permanent change. As such, chronic dieters might best be advised to abandon their dieting attempts.

Food intake and physical activity: a comparison of three measures of dieting

We examined food preferences, dietary intake, and physical activity in dieters and nondieters using three different methods of dieting classification. One hundred three women and 99 men completed the cognitive restraint subscale of Stunkard and Messick's (1985) Three Factor Eating Questionnaire (TFEQ-R) and Herman and Polivy's (1980) Restraint Scale (RS), and answered questions about their current efforts to lose or maintain weight. Women identifying themselves as currently dieting to lose weight reported expending twice as much energy in physical activity compared to those reporting that they were either currently dieting to maintain weight or not dieting. There were no significant differences in dietary intake or physical activity by current dieting status in men. Women chronic dieters identified by high TFEQ-R scores reported lower total calorie intake and less frequent sweets consumption than women with low TFEQ-R scores. In men, those with high TFEQ-R scores reported consuming a greater percent of calories from protein and carbohydrate, less beef, pork, whole milk, and sweets. In women, the RS did not distinguish dieters from nondieters on any measure. In men, the RS results were similar to those from the TFEQ-R. These results show that current measures of dieting are only weakly related to behaviors thought to be indicative of dieting. Future research must develop more precise measures of dieting in order to examine the relationship between self-reports of dieting and behaviors thought to be related to dieting.