Weight loss and its maintenance for type 2 diabetes prevention – the PREVIEW study

Abstract

Background: Overweight and obesity are risk factors for type-2 diabetes (T2D) but an effective lifestyle modification strategy to prevent weight gain and, consequently, T2D is yet to be identified. Aims: PREVIEW - PREVention of diabetes through lifestyle intervention and population studies in Europe and Worldwide– is a large scale program, recruiting overweight and obese adults and children known to be at high risk of developing T2D, taking place in 11 countries worldwide. The intervention aims to determine whether a higher protein lower glycaemic index (GI) diet is more effective for weight loss maintenance and diabetes prevention than a moderate protein, moderate GI diet. PREVIEW will also investigate the additional effect of moderate vs. high intensity exercise in T2D prevention. Methods: 2,326 overweight (BMI≥25.0 kg/m2) adults and children were recruited. Participants completed an 8 week weight loss program using a low calorie diet (LCD, 4MJ/d), and those who achieved ≥8% weight loss were enrolled in a long-term (3 year) weight loss maintenance program to completed in 2018. Diets are ad libitum. Intensive dietary and exercise counselling takes place in groups of 8-12 individuals. Biological samples are collected for assessment of markers of T2D and cardiovascular disease (CVD). The primary endpoint is the incidence of T2D at 3 years, based on a 75g oral glucose tolerance test (OGTT). Results: 1,842 participants (67% women) completed the weight loss phase successfully. At baseline, mean (±SD) age was 51.6±11.6 years, BMI 35.3±6.5 kg/m2. Participants lost 10.6±4.0 kg during the LCD, with men losing more absolute weight than women (P<0.001). HbA1c decreased by 2.2±0.09 mmol/mol in men, and by 1.8±0.06 mmol/mol in women (P<0.001). Conclusion: 8 weeks of LCD intervention resulted in a marked decrease in body weight and decreased the risk of T2D among pre-diabetic individuals. Significantly larger decreases were seen in men versus women.