Impact of a reduced red and processed meat dietary pattern on disease risks and greenhouse gas emissions in the UK: a modelling study.

OBJECTIVES: Consumption of red and processed meat (RPM) is a leading contributor to greenhouse gas (GHG) emissions, and high intakes of these foods increase the risks of several leading chronic diseases. The aim of this study was to use newly derived estimates of habitual meat intakes in UK adults to assess potential co-benefits to health and the environment from reduced RPM consumption. DESIGN: Modelling study using dietary intake data from the National Diet and Nutrition Survey of British Adults. SETTING: British general population. METHODS: Respondents were divided into fifths by energy-adjusted RPM intakes, with vegetarians constituting a sixth stratum. GHG emitted in supplying the diets of each stratum was estimated using data from life-cycle analyses. A feasible counterfactual UK population was specified, in which the proportion of vegetarians measured in the survey population doubled, and the remainder adopted the dietary pattern of the lowest fifth of RPM consumers. OUTCOME MEASURES: Reductions in risks of coronary heart disease, diabetes and colorectal cancer, and GHG emissions, under the counterfactual. RESULTS: Habitual RPM intakes were 2.5 times higher in the top compared with the bottom fifth of consumers. Under the counterfactual, statistically significant reductions in population aggregate risks ranged from 3.2% (95% CI 1.9 to 4.7) for diabetes in women to 12.2% (6.4 to 18.0) for colorectal cancer in men, with those moving from the highest to lowest consumption levels gaining about twice these averages. The expected reduction in GHG emissions was 0.45 tonnes CO(2) equivalent/person/year, about 3% of the current total, giving a reduction across the UK population of 27.8 million tonnes/year. CONCLUSIONS: Reduced consumption of RPM would bring multiple benefits to health and environment.

Primary care referral to a commercial provider for weight loss treatment versus standard care: a randomised controlled trial.

BACKGROUND: The increasing prevalence of overweight and obesity needs effective approaches for weight loss in primary care and community settings. We compared weight loss with standard treatment in primary care with that achieved after referral by the primary care team to a commercial provider in the community. METHODS: In this parallel group, non-blinded, randomised controlled trial, 772 overweight and obese adults were recruited by primary care practices in Australia, Germany, and the UK. Participants were randomly assigned with a computer-generated simple randomisation sequence to receive either 12 months of standard care as defined by national treatment guidelines, or 12 months of free membership to a commercial programme (Weight Watchers), and followed up for 12 months. The primary outcome was weight change over 12 months. Analysis was by intention to treat (last observation carried forward [LOCF] and baseline observation carried forward [BOCF]) and in the population who completed the 12-month assessment. This trial is registered, number ISRCTN85485463. FINDINGS: 377 participants were assigned to the commercial programme, of whom 230 (61%) completed the 12-month assessment; and 395 were assigned to standard care, of whom 214 (54%) completed the 12-month assessment. In all analyses, participants in the commercial programme group lost twice as much weight as did those in the standard care group. Mean weight change at 12 months was -5·06 kg (SE 0·31) for those in the commercial programme versus -2·25 kg (0·21) for those receiving standard care (adjusted difference -2·77 kg, 95% CI -3·50 to -2·03) with LOCF; -4·06 kg (0·31) versus -1·77 kg (0·19; adjusted difference -2·29 kg, -2·99 to -1·58) with BOCF; and -6·65 kg (0·43) versus -3·26 kg (0·33; adjusted difference -3·16 kg, -4·23 to -2·11) for those who completed the 12-month assessment. Participants reported no adverse events related to trial participation. INTERPRETATION: Referral by a primary health-care professional to a commercial weight loss programme that provides regular weighing, advice about diet and physical activity, motivation, and group support can offer a clinically useful early intervention for weight management in overweight and obese people that can be delivered at large scale. FUNDING: Weight Watchers International, through a grant to the UK Medical Research Council.

Weight Watchers on prescription: an observational study of weight change among adults referred to Weight Watchers by the NHS.

BACKGROUND: The scale of overweight and obesity in the UK places a considerable burden on the NHS. In some areas the NHS has formed partnerships with commercial companies to offer weight management services, but there has been little evaluation of these schemes.This study is an independent audit of the Weight Watchers NHS Referral scheme and evaluates the weight change of obese and overweight adults referred to Weight Watchers (WW) by the NHS. METHOD: Data was obtained from the WW NHS Referral Scheme database for 29,326 referral courses started after 2nd April 2007 and ending before 6th October 2009 [90% female; median age 49 years (IQR 38-61 years); median BMI 35.1 kg/m2 (IQR 31.8-39.5 kg/m2). Participants received vouchers (funded by the PCT following referral by a healthcare professional) to attend 12 WW meetings. Body weight was measured at WW meetings and relayed to the central database. RESULTS: Median weight change for all referrals was -2.8 kg [IQR -5.9--0.7 kg] representing -3.1% initial weight. 33% of all courses resulted in loss of ≥5% initial weight. 54% of courses were completed. Median weight change for those completing a first course was -5.4 kg [IQR -7.8--3.1 kg] or -5.6% of initial weight. 57% lost ≥5% initial weight. CONCLUSIONS: A third of all patients who were referred to WW through the WW NHS Referral Scheme and started a 12 session course achieved ≥5% weight loss, which is usually associated with clinical benefits. This is the largest audit of NHS referral to a commercial weight loss programme in the UK and results are comparable with other options for weight loss available through primary care.

Measuring health: a practical challenge with a philosophical solution?

With the current demographic shift being experienced by populations globally, almost linear increases in life expectancy have been seen and can be expected. However, increases in healthy life expectancy may not keep pace. Among older populations the proportion of time spent in less than full health tends to increase. As a result, the accurate valuation of life spent in states less than full health will become increasingly important. Different techniques and approaches have been used to measure health in populations. The use of summary measures of population health such as DALYs (Disability Adjusted Life Years) has become common, and is widely used to compare health between populations and to evaluate the potential impact of interventions in economic analyses. Most of the commonly used summary measures of health express some measure of life lived in full health and life lived with disability or in a state of sub-optimal health. Critical to the construction of summary health measures are values assigned to health states. Current tools used in determining these values include the standard gamble, time trade off, person trade off, and the visual analogue scale. However, these techniques all have the disadvantage of incorporating individual biases (derived from particular characteristics specific to individuals or populations) into the process through which health state valuations are derived. As a consequence health states are often not directly comparable between populations, since characteristics such as nationality and ethnicity can influence how health states are valued. Furthermore, health can be judged differently by those of different ages, with the young often assigning a lower value to life lived at less than full health compared to older people. The challenge of obtaining opinions which are not influenced by an individual's own circumstances is not new. This issue was encountered and described by the American philosopher John Rawls in 'A Theory of Justice' (1971), in which he employed a thought experiment called 'the veil of ignorance' as a means of overcoming this problem. In this thought experiment an individual is asked to make decisions about distributive justice by imagining they are behind a 'veil of ignorance', whereby they are unaware of their own position in society. Here we discuss how current methods for deriving health state values may incorporate a veil of ignorance approach, and how this may benefit the comparability of the health state valuations produced. We also propose how such methods may be operationalized. Considering these issues, we propose that a new society with new needs and a progressively growing interest in maintaining adequate health requires appropriate measures of health. These measures should facilitate derivation of objective measures of health that are comparable to those acquired in other populations, irrespective of age, gender, disease status, ethnicity and geographical location. Promoting and improving health demands adequate measures of health and the application of the Rawlsian veil of ignorance approach could be an effective alternative.

Effects of worksite health promotion interventions on employee diets: a systematic review.

BACKGROUND: Public health strategies place increasing emphasis on opportunities to promote healthy behaviours within the workplace setting. Previous research has suggested worksite health promotion programmes have positive effects on physical activity and weight loss, yet little is known regarding their effects on dietary behaviour. The aim of this review was to assess the effects of worksite interventions on employee diets. METHODS: Electronic databases (MEDLINE, The Cochrane Library, PsycINFO, EMBASE, LexisNexis) were searched for relevant articles published between 1995 and April 2009. Studies were eligible for inclusion if they were peer-reviewed English language publications describing a worksite-based health promotion intervention with minimum study duration of eight weeks. All study designs were eligible. Studies had to report one or more diet-related outcome (energy, fat, fruit, or vegetable intakes). Methodological quality was assessed using a checklist that included randomisation methods, use of a control group, and study attrition rates. RESULTS: Sixteen studies were included in the review. Eight programmes focussed on employee education, and the remainder targeted change to the worksite environment, either alone or in combination with education. Study methodological quality was moderate. In general, worksite interventions led to positive changes in fruit, vegetable and total fat intake. However, reliance on self-reported methods of dietary assessment means there is a significant risk of bias. No study measured more robust outcomes such as absenteeism, productivity, or healthcare utilisation. CONCLUSIONS: The findings of this review suggest that worksite health promotion programmes are associated with moderate improvement in dietary intake. The quality of studies to date has been frequently sub-optimal and further, well designed studies are needed in order to reliably determine effectiveness and cost-effectiveness. Future programmes to improve employee dietary habits should move beyond individual education and aim to intervene at multiple levels of the worksite environment.

No difference in the 24-hour interstitial fluid glucose profile with modulations to the glycemic index of the diet.

OBJECTIVE: Reducing the glycemic index (GI) of the diet may decrease metabolic risk, primarily through reduction and stabilization of blood glucose. The objective of this research was to investigate whether incorporation of lower or higher GI foods into mixed meals had different effects on daylong glucose profiles, measured in interstitial fluid by a continuous glucose-monitoring system. METHODS: The study was a randomized, balanced, two-way crossover intervention of 2 x 1-wk periods of lower and higher GI diets. Participants were 12 overweight healthy adult women (mean body mass index +/- standard deviation 27.5+/-2.3 kg/m(2)). Changes in GI were achieved through substitution of key staple carbohydrate-rich foods. After a 4-d run-in on each dietary regimen, participants wore the continuous glucose-monitoring system over 2 d of identical controlled feeding in the laboratory, separated by 1 d of ad libitum consumption at home. RESULTS: On controlled days, diets differed in GI by 15 U and provided equal energy, macronutrients, and fiber. On ad libitum days, diet diaries revealed a difference in GI of 14+/-1 U (mean +/- standard error), with no detectable difference in energy, macronutrient, or fiber intake. No differences were observed in glucose profiles between higher and lower GI interventions in the controlled or ad libitum setting. There was significant agreement in area under the glucose curve on repeated controlled feeding days (intraclass correlation 0.75). CONCLUSION: This study indicates that a difference in dietary GI of 14-15 U is insufficient to alter daylong glycemia as measured in interstitial fluid by the continuous glucose-monitoring system.

Glycaemic index and metabolic disease risk.

There is growing evidence that the type of carbohydrate consumed is important in relation to metabolic disease risk, and there is currently particular interest in the role of low-glycaemic-index (GI) foods. Observational studies have associated low-GI diets with decreased risk of type 2 diabetes and CHD, and improvements in various metabolic risk factors have been seen in some intervention studies. However, findings have been mixed and inconsistent. There are a number of plausible mechanisms for the effects of these foods on disease risk, which arise from the differing metabolic responses to low- and high-GI foods, with low-GI foods resulting in reductions in hyperglycaemia, hyperinsulinaemia and late postprandial circulating NEFA levels. Low-GI foods may also increase satiety and delay the return of hunger compared with high-GI foods, which could translate into reduced energy intake at later time points. However, the impact of a low-GI diet on body weight is controversial, with many studies confounded by dietary manipulations that differ in aspects other than GI. There is currently much interest in GI from scientists, health professionals and the public, but more research is needed before clear conclusions can be drawn about relationships with metabolic disease risk.