Objective: To review evidence relating to the consumption of whole grains and healthy body weight (BW). Design: Systematic review and analysis of observational studies reporting wholegrain consumption and measures of BW and adiposity, including the effect on macronutrient intakes and lifestyle factors. Setting: Medline and other databases were searched for the period 1990 to 2006 to produce a full reference list; observational studies were retained for further analysis if they included an appropriate control group and reported whole-grain intake and body mass index (BMI) or a measure of adiposity. Subjects: Fifteen trials were identified which included data from 119 829 male and female subjects aged 13 years and over. Results: The combined and weighted mean difference in BMI from 15 studies representing 20 treatment groups (n 5 119 829) using a random-effects model was 0Á630 kg/m 2 lower when high versus low whole-grain intake was compared, P , 0Á0001 (95 % confidence interval (CI) 0Á460, 0Á800 kg/m 2 ). In high consumers, adiposity assessed as waist circumference was reduced by 2Á7 (95 % CI 0Á2, 5Á2) cm, P 5 0Á03 (six data sets, n 5 4178) or as waist:hip ratio by 0Á023 (95 % CI 0Á016, 0Á030), P , 0.0001 (four data sets, n 5 20 147). Higher intake of whole grains led to increased dietary fibre intake (9 g, P , 0Á01), while total and saturated fat intakes decreased by 11 g and 3Á9 g, respectively. Conclusion: A higher intake of whole grains (about three servings per day) was associated with lower BMI and central adiposity. In addition, people who consume more whole grains are likely to have a healthier lifestyle as fewer of them smoke, they exercise more frequently and they tend to have lower fat and higher fibre intakes.
Keywords
Whole grains Healthy weight Body mass index AdiposityThe challenge of obesity to the health of Western society has been clearly identified by the World Health Organization (WHO) (1) , which also recognises that maintenance of a healthy weight is in itself as large a challenge as obesity. In the UK, the Department of Health's publication, Choosing Health: Making Healthy Choices Easier, aimed to improve the understanding of the increasing rise in the overweight and obese population in the UK and from this numerous strategies and networks are being developed to reduce the prevalence of an obese population (2) . Guidance on the prevention, identification, assessment and management of overweight and obesity in adults and children was published by the National Institute for Clinical Excellence (NICE) in December 2006. The first two NICE dietary guidelines for healthy weight maintenance recommend (3) :> Base meals on starchy foods such as potatoes, bread, rice and pasta, choosing whole grains wherever possible;> Eat plenty of fibre-rich foods -such as oats, beans, peas, lentils, grains, seeds, fruit and vegetables, as well as whole-grain bread and brown rice and pasta.The recent Dietary Guidelines for Americans (4) state that 3 or more ounce equivalents of whole-grain products should b...