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.

Sarcopenia, the decline of muscle mass with age, causes impaired gait, disability and falls. It may therefore increase the risk of fracture for osteoporotic women. The aims of this study were to determine the prevalence of sarcopenia in osteopenic and osteoporotic women, and to determine if hormone replacement therapy (HRT), diet, or physical activity (PA) has a role in the prevention of sarcopenia. One hundred and thirty-one premenopausal and 82 postmenopausal (54 taking HRT) healthy women (17-77 years) volunteered for the study. Body composition was measured by dual X-ray absorptiometry (DXA). Sarcopenia was defined as a relative skeletal muscle index (RSMI) (appendicular skeletal muscle mass divided by height) below 5.45 kg/m2. Osteopenia was defined by a densitometric t-score for bone mineral density (BMD) (g/cm2) below -1.0 and osteoporosis by a t-score below -2.5. Nutrient intake was assessed using 3-day food records and physical activity (PA) was measured using the Baecke Physical Activity Questionnaire. Pearson chi-squared, independent t-tests, simple correlation and multiple regression were used to analyze the data. In premenopausal osteopenic women the prevalence of sarcopenia was 12.5%. In postmenopausal women it was 25% for those with osteopenia, and 50% for those with osteoporosis. PA was independently related to RSMI (beta=0.222, p=0.0001), but diet and HRT were not. After adjusting for PA, RSMI was not significantly related to BMD. These data suggest that the relationship between RSMI, BMD and risk of osteoporosis may largely be mediated through participation in PA. Sarcopenia screening simultaneous to BMD examinations by DXA, may be of value in identifying osteoporotic women with sarcopenia, a group that may be most in need of exercise interventions to increase muscle and BMD.

The primary purpose of the present review was to determine if the scientific evidence available for potential human health benefits of conjugated linoleic acid (CLA) is sufficient to support health claims on foods based on milk naturally enriched with cis-9, trans-11-CLA (c9,t11-CLA). A search of the scientific literature was conducted and showed that almost all the promising research results that have emerged in relation to cancer, heart health, obesity, diabetes and bone health have been in animal models or in vitro. Most human intervention studies have utilised synthetic CLA supplements, usually a 50:50 blend of c9,t11-CLA and trans-10, cis-12-CLA (t10,c12-CLA). Of these studies, the only evidence that is broadly consistent is an effect on body fat and weight reduction. A previous review of the relevant studies found that 3.2 g CLA/d resulted in a modest body fat loss in human subjects of about 0.09 kg/week, but this effect was attributed to the t10,c12-CLA isomer. There is no evidence of a consistent benefit of c9,t11-CLA on any health conditions; and in fact both synthetic isomers, particularly t10,c12-CLA, have been suspected of having pro-diabetic effects in individuals who are already at risk of developing diabetes. Four published intervention studies using naturally enriched CLA products were identified; however, the results were inconclusive. This may be partly due to the differences in the concentration of CLA administered in animal and human studies. In conclusion, further substantiation of the scientific evidence relating to CLA and human health benefits are required before health claims can be confirmed.

BackgroundGiven the worldwide prevalence of overweight and obesity, there is a clear need for meaningful practical healthy eating advice - not only in relation to food choice, but also on appropriate food portion sizes. As the majority of portion size research to date has been overwhelmingly quantitative in design, there is a clear need to qualitatively explore consumers’ views in order to fully understand how food portion size decisions are made. Using qualitative methodology this present study aimed to explore consumers’ views about factors influencing their portion size selection and consumption and to identify barriers to appropriate portion size control.MethodsTen focus groups with four to nine participants in each were formed with a total of 66 persons (aged 19–64 years) living on the island of Ireland. The semi-structured discussions elicited participants’ perceptions of suggested serving size guidance and explored the influence of personal, social and environmental factors on their food portion size consumption. Audiotapes of the discussions were professionally transcribed verbatim, loaded into NVivo 9, and analysed using an inductive thematic analysis procedure.ResultsThe rich descriptive data derived from participants highlight that unhealthy portion size behaviors emanate from various psychological, social and behavioral factors. These bypass reflective and deliberative control, and converge to constitute significant barriers to healthy portion size control. Seven significant barriers to healthy portion size control were apparent: (1) lack of clarity and irrelevance of suggested serving size guidance; (2) guiltless eating; (3) lack of self-control over food cues; (4) distracted eating; (5) social pressures; (6) emotional eating rewards; and (7) quantification habits ingrained from childhood.ConclusionsPortion size control strategies should empower consumers to overcome these effects so that the consumption of appropriate food portion sizes becomes automatic and habitual.

Objective: The present study aimed to evaluate the precision, ease of use and likelihood of future use of portion size estimation aids (PSEA). Design: A range of PSEA were used to estimate the serving sizes of a range of commonly eaten foods and rated for ease of use and likelihood of future usage. Setting: For each food, participants selected their preferred PSEA from a range of options including: quantities and measures; reference objects; measuring; and indicators on food packets. These PSEA were used to serve out various foods (e.g. liquid, amorphous, and composite dishes). Ease of use and likelihood of future use were noted. The foods were weighed to determine the precision of each PSEA. Subjects: Males and females aged 18-64 years (n 120). Results: The quantities and measures were the most precise PSEA (lowest range of weights for estimated portion sizes). However, participants preferred household measures (e.g. 200 ml disposable cup) -deemed easy to use (median rating of 5), likely to use again in future (all scored either 4 or 5 on a scale from 1 = 'not very likely' to 5 = 'very likely to use again') and precise (narrow range of weights for estimated portion sizes). The majority indicated they would most likely use the PSEA preparing a meal (94 %), particularly dinner (86 %) in the home (89 %; all P < 0·001) for amorphous grain foods. Conclusions: Household measures may be precise, easy to use and acceptable aids for estimating the appropriate portion size of amorphous grain foods.