The food restriction wars: Proposed resolution of a primary battle

Youth's energy intake during a laboratory-based loss-of-control eating paradigm: Associations with reported current dieting

Dieting is theorized as a risk factor for loss-of-control (LOC)-eating (i.e., feeling a sense of lack of control while eating). Support for this association has largely relied on retrospective self-report data, which does not always correlate with objectively assessed eating behavior in youth. We hypothesized that during a laboratory-based LOC-eating paradigm, children and adolescents who reported current (at the time of the visit) dieting would consume meals consistent with LOC-eating (greater caloric intake, and intake of carbohydrates and fats, but less intake of protein). Participants were presented with a buffet-style meal and instructed to "Let yourself go and eat as much as you want." Current dieting (i.e., any deliberate change to the amount or type of food eaten to influence shape or weight, regardless of how effective the changes are) was assessed via interview. General linear models were adjusted for fat mass (%), lean mass (kg), height, sex, protocol, race and ethnicity, pre-meal hunger and minutes since consumption of a breakfast shake. Of 337 participants (Mage 12.8 ± 2.7y; 62.3 % female; 45.7 % non- Hispanic White and 26.1 % non-Hispanic Black; MBMIz 0.78 ± 1.11), only 33 (9.8 %) reported current dieting. Current dieting was not significantly associated with total energy intake (F = 1.63, p = .20, ηp2 = 0.005), or intake from carbohydrates (F = 2.45, p = .12, ηp2 = 0.007), fat (F = 2.65, p = .10, ηp2 = 0.008), or protein (F = 0.39, p = .53, ηp2 = 0.001). Contrary to theories that dieting promotes LOC-eating, current dieting was not associated with youth's eating behavior in a laboratory setting. Experimental approaches for investigating dieting are needed to test theories that implicate dieting in pediatric LOC-eating.

Distinguishing probable atypical anorexia nervosa from weight loss alone in a national sample of U.S. Military Veterans: Disentangling the roles of weight suppression and cognitive concerns

OBJECTIVE

Veterans are at high risk for eating disorders (EDs), and specifically for atypical anorexia nervosa (atypical AN). The current study aimed to better understand this under-studied disorder and how it differs from weight loss without ED cognitive features.

METHOD

Secondary analyses were conducted with data from a national study of Veterans (N = 882, 49.4% women). Participants were categorized into four mutually exclusive groups using the Eating Disorder Diagnostic Scale 5: probable atypical AN, a cognitive concerns group (Cog Only), a weight suppressed group (WS Only), and a no ED control group. Adjusted regression models were used to compare groups on measures of eating pathology and mental health. Three weight suppression thresholds (5%, 10%, and 15%) for probable atypical AN were also tested.

RESULTS

The sample was comprised of 12% probable atypical AN, 23.6% Cog Only, 16.3% WS Only, and 48.1% Control. The probable atypical AN group was most like the Cog Only group except for higher levels of dietary restraint. Atypical AN fared worse and was least like the Control group followed by the WS Only group. All weight suppression thresholds significantly predicted dietary restraint, with 5% being the best predictor.

DISCUSSION

Results found that probable atypical AN is a distinct clinical entity and that the exact weight suppression threshold associated with atypical AN is less important than having any weight suppression. Findings highlight the clinical significance of atypical AN and the importance of gaining a better understanding of how to address this clinical entity.

PUBLIC SIGNIFICANCE

Atypical anorexia nervosa is a relatively underexamined but highly prevalent eating disorder in the Veteran population. Results show that ED cognitive features are more closely linked to clinically significant eating pathology and poor mental health than weight suppression alone suggesting that negative thinking about weight gain and appearance, regardless of the presence or severity of weight loss, may signal the need for specialized intervention.

Testing replicability of the relationship between weight suppression and binge eating in three non-clinical samples varying in lifetime weight history

OBJECTIVE

Increased weight suppression, the difference between an individual's highest and current weight at present height, predicts binge eating among eating disorder samples. Less is known about this relationship in non-clinical samples of individuals with a history of higher weight.

METHODS

Lifetime highest BMI was tested as a moderator of the relationship between weight suppression and binge eating in three independent samples (N = 1740).

RESULTS

At the bivariate level, weight suppression was not associated with binge eating in any sample (p's ≥ 0.20). Lifetime highest BMI moderated the relationship between weight suppression and binge eating in Sample 1 (p = .04), such that greater weight suppression was associated with lower binge eating among those with a history of higher weight (i.e., BMI = 40 kg/m2). In Samples 2 and 3, the lifetime highest BMI by weight suppression interaction term was not significant and dropped from the model (p's = 0.10-0.12). Accounting for age, gender, and lifetime highest BMI, greater weight suppression was associated with lower binge eating scores (p's < 0.04). A meta-analysis combining results revealed a small but significant interaction effect (r = 0.07, p = .02).

CONCLUSIONS

Findings highlight the importance of investigating the generalizability of eating disorder risk and maintenance theories across the weight spectrum. Weight loss may not increase risk for binge eating among those with a history of higher weight. Future work should replicate and extend this finding using longitudinal designs. More research is needed to elucidate which weight loss motivations and/or behaviors are most closely linked to binge eating.

To Eat or Not to Eat-A Qualitative Exploration and Typology of Restrictive Dietary Practices among Middle-Aged and Older Adults

Favorable diets often include restrictive practices that have proven health benefits, even if initiated later in life. The aim of this qualitative study is to gain a comprehensive understanding of Restrictive Dietary Practices (RDPs) among a sample of middle-aged and older German adults (aged 59-78 years). We conducted 24 narrative in-depth interviews and analyzed the data using qualitative content analysis (Kuckartz). Following an inductive thematic approach, a typology was reconstructed comprising four typical RDP characteristics: I. The Holistically Restraining Type, II. The Dissonant-savoring Restraining Type, III. The Reactively Restraining Type, and IV. The Unintentionally Restraining Type. These types differed regarding the practical implementation of, e.g., restrictive food choice into everyday routines, barriers to do so, as well as with respect to attitudes and motives underlying RDPs. The major motives for adopting a RDP involved health, well-being, ethical, and ecological concerns. The most prominent barriers to a 'successful' adoption of RDPs were the enjoyment of food and the desire for spontaneity and freedom of (food) choice. Our study offers an in-depth understanding of the aspects that shape the widespread practice of dietary restriction among middle-aged and older adults. Lifeworld-related changes in RDPs and possible 'type shiftings' are discussed as well as the meaning and chances of RDPs for public health promotion.

Reduction of NADPH oxidase 4 in adipocytes contributes to the anti-obesity effect of dihydroartemisinin

Artemisinin derivatives have been found to have anti-obesity effects recently, but the mechanism is still controversial. Herein, long-term DHA treatment in obese mice significantly reduced the body weight and improved glucose metabolism. However, short-term DHA treatment did not affect glucose metabolism in obese mice, suggesting that the improved glucose metabolism in mice with DHA treatment could be secondary to body weight reduction. Consistent with previous reports, we observed that DHA inhibited the differentiation of adipocytes. Mechanistically, DHA significantly reduced the expression of NADPH oxidase 4 (NOX4) in white adipose tissue (WAT) of mice and differentiated adipocytes, and using NOX4 siRNA or the NOX4 inhibitor GKT137831 significantly attenuated adipocyte differentiation. Over-expression of NOX4 partially reversed the inhibition effect of DHA on adipogenic differentiation of preadipocytes. In addition, targeted proteomics analysis showed that DHA improved the abnormality of metabolic pathways. In conclusion, DHA significantly reduced fat mass and improved glucose metabolism in obese mice, possibly by inhibiting NOX4 expression to suppress adipocyte differentiation and lipid accumulation in adipocytes.

Content analysis of the impact of COVID-19 on weight and shape control behaviors and social media content of U.S. adolescents and young adults

OBJECTIVE

The current study examines impacts of the COVID-19 pandemic on weight/shape control behaviors among adolescents and young adults in the U.S., and perceived changes to related social media content.

METHOD

A sample of youth (14-24 years) from MyVoice, a national text-message-based cohort, provided open-ended responses to questions on changes in eating and exercise habits due to concern about weight/shape, and social media content related to weight/shape, during the pandemic. Responses were collected using a secure online platform and analyzed using content analysis.

RESULTS

Among respondents (n = 939/1153, response rate = 81%), 40.0% adopted behaviors for the purpose of weight/shape control during the pandemic. Nearly half (49.2%) reported seeing posts about weight/shape on social media during the pandemic.

DISCUSSION

Findings from this study indicate that weight/shape concerns among adolescents and young adults in the U.S. may have increased due to the COVID-19 pandemic, with social media content as a potentially contributing factor.

The Complicated Relationship between Dieting, Dietary Restraint, Caloric Restriction, and Eating Disorders: Is a Shift in Public Health Messaging Warranted?

The origins of theories specifying dietary restraint as a cause of eating disorders can be traced to the 1970s. This paper will present an overview of the origins of dietary restraint theories and a brief historical review of evidence will be summarized. Recent research will be presented, including the results from the CALERIE Phase 1 study, as well as CALERIE Phase 2, which were NIH-sponsored randomized controlled trials. CALERIE 2 provided a test of the effect of two years of caloric restriction (CR) on the development of eating disorder syndromes and symptoms in comparison to a control group that did not alter eating behavior or body weight. The intervention was effective for inducing a chronic (two-year) reduction in total energy expenditure and increased dietary restraint but did not increase symptoms of eating disorders. The results of this recent investigation and other studies have not provided experimental support for conventional dietary restraint theories of eating disorders. These findings are discussed in terms of potential revisions of dietary restraint theory, as well as the implications for a paradigm shift in public health messaging related to dieting.