Randomised controlled trial of four commercial weight loss programmes in the UK: initial findings from the BBC “diet trials”

Abstract

Objective To compare the effectiveness of four commercial weight loss diets available to adults in the United Kingdom. Design Six month multicentre randomised unblinded controlled trial. Setting Community based sample of otherwise healthy overweight and obese adults. Interventions Dr Atkins' new diet revolution, Slim-Fast plan, Weight Watchers pure points programme, and Rosemary Conley's eat yourself slim diet and fitness plan. Main outcome measures Weight and body fat changes over six months. Results All diets resulted in significant loss of body fat and weight over six months. Groups did not differ significantly but loss of body fat and weight was greater in all groups compared with the control group. In an intention to treat analysis, average weight loss was 5.9 kg and average fat loss was 4.4 kg over six months. The Atkins diet resulted in significantly higher weight loss during the first four weeks, but by the end was no more or less effective than the other diets. Conclusions Clinically useful weight loss and fat loss can be achieved in adults who are motivated to follow commercial diets for a substantial period. Given the limited resources for weight management in the NHS, healthcare practitioners should discuss with their patients programmes known to be effective. Trial registration Clinical trials NCT00327821.

Comparison of the effects of four commercially available weight-loss programmes on lipid-based cardiovascular risk factors

“…Thus every effort was made to avoid investigator management of, or interference in, participants' food intakes. As discussed elsewhere (17) , there were no differences in diet, centre or gender in terms of the proportions of participants who completed or withdrew. The analysis of completers showed that, within each group, there was variable compliance resulting in a large range of weight loss for each of the four regimes, but all four diets tested were equally effective at promoting weight loss over 6 months.…”

“…There was no significant change in weight in the control group. A full examination of weight outcomes has been reported previously (17) . Markers of renal function were maintained within normal limits for all Atkins participants.…”

“…Furthermore, with the notable exception of one recent study (15) , there have been few direct comparisons of the efficacy of commercially available weight-loss programmes in modifying blood lipids and lipoproteins. The present multi-centred study, the largest in the UK to date, was designed to examine the efficacy of four popular weightloss programmes, in a randomised controlled design, on a range of outcome variables related to weight loss, body composition and biochemical variables that have been reported elsewhere (16,17) . The current paper reports the effects of these diets on plasma lipid and lipoproteins as markers of CVD risk.…”

Habitual dietary intake, eating pattern and physical activity of women with polycystic ovary syndrome

“…Participants completed a questionnaire and a 7-day estimated food and activity diary (previously used in published studies (Truby et al, 2006)). The questionnaire was designed specifically for this study and included questions relating to diagnosis, self-reported symptoms (What conditions/symptoms do you have as a result of your PCOS?…”

Low-carbohydrate–high-protein diet and long-term survival in a general population cohort

“…Many of these diets emphasize reduction of carbohydrate intake and thereby encourage high protein intake, given that, in Western countries, highfat diets are also generally avoided (Astrup et al, 2004). There is evidence that low carbohydrate-high protein (LC/HP) diets do indeed lead to better weight control or even weight loss in the short term (Foster et al, 2003;Samaha et al, 2003;Willett, 2004;Truby et al, 2006). In contrast, according to a randomized trial that examined for a year the effectiveness of four popular diets (Atkins, Zone, Weight Watchers, Ornish), the amount of weight loss and the changes in biochemical parameters were not significantly different among diets and were only evident among committed dieters (Dansinger et al, 2005).…”