Cognitive and weight-related correlates of flexible and rigid restrained eating behaviour.

OBJECTIVES: Examine the association between components of restrained eating, cognitive performance and weight loss maintenance. METHODS: 106 women, all members of a commercial slimming organisation for at least 6 months (mean±SD: 15.7±12.4 months), were studied who, having lost 10.1±9.7 kg of their initial weight, were hoping to sustain their weight loss during the 6 month study. Dietary restraint subcomponents flexible and rigid restraint, as well as preoccupying cognitions with food, body-shape and diet were assessed using questionnaires. Attentional bias to food and shape-related stimuli was measured using a modified Stroop test. Working memory performance was assessed using the N-back test. These factors, and participant weight, were measured twice at 6 month intervals. RESULTS: Rigid restraint was associated with attentional bias to food and shape-related stimuli (r=0.43, p<0.001 resp. r=0.49, p<0.001) whereas flexible restraint correlated with impaired working memory (r=-0.25, p<0.05). In a multiple regression analyses, flexible restraint was associated with more weight lost and better weight loss maintenance, while rigid restraint was associated with less weight loss. CONCLUSIONS: Rigid restraint correlates with a range of preoccupying cognitions and attentional bias to food and shape-related stimuli. Flexible restraint, despite the impaired working memory performance, predicts better long-term weight loss. Explicitly encouraging flexible restraint may be important in preventing and treating obesity.

Micronutrient quality of weight-loss diets that focus on macronutrients: results from the A TO Z study.

BACKGROUND: Information on the micronutrient quality of alternative weight-loss diets is limited, despite the significant public health relevance. OBJECTIVE: Micronutrient intake was compared between overweight or obese women randomly assigned to 4 popular diets that varied primarily in macronutrient distribution. DESIGN: Dietary data were collected from women in the Atkins (n = 73), Zone (n = 73), LEARN (Lifestyle, Exercise, Attitudes, Relationships, Nutrition) (n = 73), and Ornish (n = 72) diet groups by using 3-d, unannounced 24-h recalls at baseline and after 8 wk of instruction. Nutrient intakes were compared between groups at 8 wk and within groups for 8-wk changes in risk of micronutrient inadequacy. RESULTS: At 8 wk, significant differences were observed between groups for all macronutrients and for many micronutrients (P < 0.0001). Energy intake decreased from baseline in all 4 groups but was similar between groups. At 8 wk, a significant proportion of individuals shifted to intakes associated with risk of inadequacy (P < 0.05) in the Atkins group for thiamine, folic acid, vitamin C, iron, and magnesium; in the LEARN group for vitamin E, thiamine, and magnesium; and in the Ornish group for vitamins E and B-12 and zinc. In contrast, for the Zone group, the risk of inadequacy significantly decreased for vitamins A, E, K, and C (P < 0.05), and no significant increases in risk of inadequacy were observed for other micronutrients. CONCLUSIONS: Weight-loss diets that focus on macronutrient composition should attend to the overall quality of the diet, including the adequacy of micronutrient intakes. Concerning calorie-restricted diets, there may be a micronutrient advantage to diets providing moderately low carbohydrate amounts and that contain nutrient-dense foods.

[Assessment of the nutritional value of slimming diets]. / Ocena wartosci odzywczej diet odchudzajacych.

The aim of the study was assessment of the nutritional value of slimming diets published in women's magazines. For this purpose, 12 diets from the magazines issued in the years 2004-2005 were chosen. In the most of analysed diets, content of nutrients differed from the recommended values. The abnormalities mainly applied to incorrect supply of energy and dietary fibre, in half of them, and protein and fat in one third of them, as well as insufficient supply of calcium, iron, copper and most of analysed B group vitamins e.g. vitamin B1 and B2 were noticed.

Safety of low-carbohydrate diets.

Low-carbohydrate diets have re-emerged into the public spotlight and are enjoying a high degree of popularity as people search for a solution to the population's ever-expanding waistline. The current evidence though indicates that low-carbohydrate diets present no significant advantage over more traditional energy-restricted diets on long-term weight loss and maintenance. Furthermore, a higher rate of adverse side-effects can be attributed to low-carbohydrate dieting approaches. Short-term efficacy of low-carbohydrate diets has been demonstrated for some lipid parameters of cardiovascular risk and measures of glucose control and insulin sensitivity, but no studies have ascertained if these effects represent a change in primary outcome measures. Low-carbohydrate diets are likely effective and not harmful in the short term and may have therapeutic benefits for weight-related chronic diseases although weight loss on such a program should be undertaken under medical supervision. While new commercial incarnations of the low-carbohydrate diet are now addressing overall dietary adequacy by encouraging plenty of high-fibre vegetables, fruit, low-glycaemic-index carbohydrates and healthier fat sources, this is not the message that reaches the entire public nor is it the type of diet adopted by many people outside of the world of a well-designed clinical trial. Health effects of long-term ad hoc restriction of inherently beneficial food groups without a concomitant reduction in body weight remains unanswered.

Medical nutrition therapy of overweight adolescents.

The long-term goal of medical nutrition therapy for adolescents who are overweight or at risk for becoming overweight is to promote healthy lifestyle behaviors. These behaviors will, in turn, improve metabolic parameters and self-esteem while helping the adolescent achieve and maintain a desirable body weight. The identification of anthropometric, metabolic, nutritional, and environmental risk factors present in the child and family will help formulate the medical nutrition intervention. A well-balanced diet that supports growth and development, aerobic exercise, and cognitive behavioral strategies are essential components of an intervention program. Frequent and long-term monitoring by a registered dietitian and pediatrician will reinforce lifestyle changes and support the adolescent and family in achieving realistic goals of weight loss or weight maintenance. This article covers the assessment and interventions necessary for successful nutrition therapy for obese and superobese adolescents.

Weight-loss with low or high carbohydrate diet?

OBJECTIVE: With obesity being recognized as an important cardiovascular risk factor, it is important to determine the optimal hypocaloric diet for decreasing that risk. The goal of this study was to compare the effects of two hypocaloric diets of similar caloric value, but differing in carbohydrate content (25% and 45%). SUBJECTS: Sixty-eight out-patients were followed for 12 w. DESIGN: The patients were assigned to one of two groups that received either a low (25% CHO, n = 31) or a high (45% CHO, n = 37) carbohydrate hypocaloric diet (5.0 MJ/d, 1200 Kcal/d). RESULTS: After 12 w, the mean weight loss was similar and did not differ significantly between the two groups: 10.2 +/- 0.7 kg (25% CHO) and 8.6 +/- 0.8 kg (45% CHO). Furthermore, loss of adipose tissue was similar, 8.1 +/- 0.5 kg (25% CHO) and 7.1 +/- 0.7 kg (45% CHO). Despite a high protein intake (1.4 g/kg/ideal body weight) there was loss of lean body mass: 2.2 +/- 0.4 kg (25% CHO) and 1.4 +/- 0.3 kg (45% CHO). The waist/hip ratio diminished significantly (P < 0.001) and identically in both groups. The fasting blood glucose (even though normal, along with cholesterol and triglyceride concentrations, were significantly decreased after weight loss. The fasting blood insulin which was mildly elevated before weight loss decreased more markedly with the 25% CHO diet compared to the 45% CHO diet (P < 0.003). The glucose/insulin ratio improved significantly (P < 0.05) after weight loss with both diets (0.17 +/- 0.04 mmol/mU (25% CHO) vs 0.10 +/- 0.03 mmol/mU (45% CHO). CONCLUSIONS: Neither diet offered a significant advantage when comparing weight loss or other, metabolic parameters over a 12 w period. However, considering the greater improvement of fasting blood insulin, the glucose/insulin ratio and blood triglyceride, the low carbohydrate diet (25%) could be more favourable in the long-term. The improvement of fasting blood insulin could be explained by the differences in monounsaturated fat composition in the low carbohydrate diet.

The diet game. Weighing the options.

As a major source of nutrition information for the public, physicians have a responsibility to assist their patients to make safe choices about weight loss programs. While most diet programs result in weight loss, the "quick fix" potentially is harmful. This article describes weight control options and their strengths and weaknesses.