Experience and acceptability of diets of varying protein content and glycemic index in an obese cohort: results from the Diogenes trial.

BACKGROUND/OBJECTIVES: To investigate acceptability and tolerability of diets of different protein and glycemic index (GI) content aimed at weight maintenance following a phase of rapid weight loss, as part of a large pan-European dietary intervention trial. SUBJECTS/METHODS: The Diogenes study (www.diogenes-eu.org) consisted of an initial 8-week rapid weight-loss phase (800-1000 kcal/day), followed by a 6-month weight maintenance intervention with five different diets varying in protein and GI content. Measurement of a range of outcomes relating to experience of the Diogenes diets in terms of acceptability, experience and mood were recorded via end of day questionnaires throughout the study. RESULTS: Weight change during the initial weight loss phase weakly, but positively correlated with acceptability of the programme (r range=-0.08 to 0.2, P 0.05, n=685 on four of five dimensions). Success at weight maintenance positively correlated with acceptance of the programme (r range=-0.21 to -0.34, P<0.001, n=540 for all five dimensions). The diets with higher protein content were more acceptable than the low protein (LP) diets, however, no differences between the high vs low GI diets were found concerning acceptability and tolerability. CONCLUSIONS: Results suggest that moderately high protein diets, compared with LP diets, are more acceptable diets for weight control in overweight individuals.

Health professionals', expert patients' and dieters' beliefs and attitudes about obesity.

BACKGROUND: Research has suggested that patients and treatment providers hold different beliefs and models of obesity. This could impact upon the consistency and quality of interventions for weight management. The present study investigated the attitudes and beliefs of health professionals, commercial weight management advisors (expert patients) and overweight and obese dieters, towards obesity. METHODS: Data were collected using a self-administered questionnaire from 287 health professionals, 85 expert patients and 116 dieters. Respondents gave their views on obesity causation and consequences, and the most efficacious means to manage obesity. Demographic data and self-reported height and weight were also collected. Factor analysis, analysis of variance and t-tests were used to analyse the data. RESULTS: Health professionals, expert patients and dieters held similar models of obesity, identifying the same causes (lifestyle causes), consequences (medical consequences) and treatments (current recommended options) of obesity/overweight. CONCLUSIONS: The findings of the present study indicate a broader similarity between beliefs and attitudes of those involved in obesity treatment and those that they aim to treat than was previously assumed. The concordance of beliefs between patients and treatment providers is an encouraging finding and may have important implications for public health strategies in this area.

Problems in identifying predictors and correlates of weight loss and maintenance: implications for weight control therapies based on behaviour change.

Weight management is a dynamic process, with a pre-treatment phase, a treatment (including process) phase and post-treatment maintenance, and where relapse is possible during both the treatment and maintenance. Variability in the statistical power of the studies concerned, heterogeneity in the definitions, the complexity of obesity and treatment success, the constructs and measures used to predict weight loss and maintenance, and an appreciation of who and how many people achieve it, make prediction difficult. In models of weight loss or maintenance: (i) predictors explain up to 20-30% of the variance; (ii) many predictors are the sum of several small constituent variables, each accounting for a smaller proportion of the variance; (iii) correlational or predictive relationships differ across study populations; (iv) inter-individual variability in predictors and correlates of outcomes is high and (v) most of the variance remains unexplained. Greater standardization of predictive constructs and outcome measures, in more clearly defined study populations, tracked longitudinally, is needed to better predict who sustains weight loss. Treatments need to develop a more individualized approach that is sensitive to patients' needs and individual differences, which requires measuring and predicting patterns of intra-individual behaviour variations associated weight loss and its maintenance. This information will help people shape behaviour change solutions to their own lifestyle needs.