"Restrained eating" vs "trying to lose weight": how are they associated with body weight and tendency to overeat among postmenopausal women?

In an effort to control body weight, many women diet or adopt a restrained approach to eating. Although common, dieting and dietary restraint remain poorly understood. Clarification of their association with health-related factors, such as body weight and overeating, is required. In this study, we explored how dieting and dietary restraint were associated with body mass index (BMI; calculated as kg/m2) and disinhibition (tendency to overeat) in a sample of 1,071 postmenopausal women aged 45 to 75 years. In a survey of dietary attitudes and body image, we asked about current dieting status and measured restrained eating and disinhibition. Self-reported height and weight were used to calculate BMI, which was confirmed in a subset. Participants were classified by dieting status (yes/no) and level of dietary restraint (high/low by median split).We examined the independent effects of dieting and restrained eating on BMI and disinhibition. More than half of the sample (53%) reported current dieting. Dieting and dietary restraint showed opposite associations with BMI. Among dieters, BMI was 4.1 higher (95% confidence interval: 3.6 to 4.6) than among nondieters. In contrast, BMI of restrained eaters was 1.0 lower (95% confidence interval: -1.6 to -0.5) than unrestrained eaters. Dieters had higher scores for disinhibition, but disinhibition scores of restrained eaters did not differ from those of unrestrained eaters. Our results suggest that dieting and dietary restraint are not equivalent. Finding that dietary restraint is associated with lower BMI (when considered independently of dieting) suggests that restrained eating, rather than dieting, may contribute to successful weight management.

High cognitive dietary restraint is associated with increased cortisol excretion in postmenopausal women.

BACKGROUND: Cognitive dietary restraint (perceived ongoing effort to limit dietary intake to manage body weight) is common in women at all life stages. In young women, high dietary restraint has been associated with both increased excretion of cortisol (a stress hormone) and reduced bone mass. Whether this occurs in older women is unknown and is reported here for the first time. METHODS: Postmenopausal women (49-75 years old) with high (n = 41) or low (n = 37) dietary restraint were compared to examine differences in urinary cortisol excretion, body composition assessed by dual-energy x-ray absorptiometry (bone mineral density, % body fat), dietary intake, anthropometrics, current exercise, and perceived stress. RESULTS: Women with high or low dietary restraint did not differ in age, body mass index, waist-to-hip ratio, energy intake, perceived stress, current exercise, or measures of body composition. However, urinary cortisol excretion was higher in the high restraint group (248.2 +/- 61.7 nmol/d vs 204.3 +/- 66.1 nmol/d; p =.01). Multiple regression analysis indicated that restraint group (high or low) independently predicted 7.6% of the variance in cortisol excretion. CONCLUSIONS: Postmenopausal women with high dietary restraint excrete more cortisol than do those with low restraint, suggesting that dietary restraint may be a source of stress. Although this was not associated with negative health effects in this sample, further investigation is warranted.

Women with high scores for cognitive dietary restraint choose foods lower in fat and energy.

Women with high dietary restraint typically report restricting energy intake and using reduced-kilocalorie foods in an effort to achieve or maintain a certain body weight. However, previous studies of food choices associated with dietary restraint have been limited by the self-report of participants' food selections. We provided all foods consumed during a free-living 24-hour period to 62 normal-weight women with high (n=33) or low (n=29) dietary restraint, and observed choices from among similar foods varying in fat, fiber, and energy content. Women with high dietary restraint consumed less energy and chose reduced-kilocalorie and reduced-fat foods more frequently than unrestrained eaters. Group differences in choices of milk, cream cheese, mayonnaise, salad dressing, and soda were noted. Dietitians may consider frequent use of reduced-kilocalorie and reduced-fat foods a potential indicator of high dietary restraint, which may have health consequences. Accordingly, further exploration of clients' tendency to restrict dietary intake may be warranted.

Nutritional considerations for vegetarian athletes.

With the growing interest in the potential health benefits of plant-based diets, it is relevant to consider whether vegetarian dietary practices could influence athletic performance. Accordingly, this review examines whether nutrients that may differ between vegetarian and omnivorous diets could affect physical performance. We also describe recent studies that attempt to assess the effects of a vegetarian diet on performance and comment on other nutritional aspects of vegetarianism of relevance to athletes. Although well-controlled long-term studies assessing the effects of vegetarian diets on athletes have not been conducted, the following observations can be made: 1) well-planned, appropriately supplemented vegetarian diets appear to effectively support athletic performance; 2) provided protein intakes are adequate to meet needs for total nitrogen and the essential amino acids, plant and animal protein sources appear to provide equivalent support to athletic training and performance; 3) vegetarians (particularly women) are at increased risk for non-anemic iron deficiency, which may limit endurance performance; and 4) as a group, vegetarians have lower mean muscle creatine concentrations than do omnivores, and this may affect supramaximal exercise performance. Because their initial muscle creatine concentrations are lower, vegetarians are likely to experience greater performance increments after creatine loading in activities that rely on the adenosine triphosphate/phosphocreatine system. 5) Coaches and trainers should be aware that some athletes may adopt a vegetarian diet as a strategy for weight control. Accordingly, the possibility of a disordered eating pattern should be investigated if a vegetarian diet is accompanied by unwarranted weight loss.