The <scp>PREVIEW</scp> intervention study: Results from a 3‐year randomized 2 x 2 factorial multinational trial investigating the role of protein, glycaemic index and physical activity for prevention of type 2 diabetes
Anne Raben, Pia Siig Vestentoft, Jennie Brand‐Miller, Elli Jalo, Mathijs Drummen, Liz Simpson, J. Alfredo Martínéz, Teodora Handjieva‐Darlenska, Gareth Stratton, Maija Huttunen‐Lenz, Tony Lam, Jouko Sundvall, Roslyn Muirhead, Sally D. Poppitt, Christian Ritz, Kirsi H. Pietiläinen, Margriet S. Westerterp‐Plantenga, Moira A. Taylor, Santiago Navas‐Carretero, Svetoslav Handjiev, Melitta A. McNarry, Sylvia Hansen, Laura Råman, Shannon Brodie, Marta P. Silvestre, Tanja C. Adam, Ian Macdonald, Rodrigo San-Cristóbal, Nadka Boyadjieva, Kelly A. Mackintosh, Wolfgang Schlicht, Amy Liu, Thomas Meinert Larsen, Mikael Fogelholm
Abstract
AIM: To compare the impact of two long-term weight-maintenance diets, a high protein (HP) and low glycaemic index (GI) diet versus a moderate protein (MP) and moderate GI diet, combined with either high intensity (HI) or moderate intensity physical activity (PA), on the incidence of type 2 diabetes (T2D) after rapid weight loss. MATERIALS AND METHODS: ) with prediabetes were enrolled. The primary endpoint was 3-year incidence of T2D analysed by diet treatment. Secondary outcomes included glucose, insulin, HbA1c and body weight. RESULTS: The total number of T2D cases was 62 and the cumulative incidence rate was 3.1%, with no significant differences between the two diets, PA or their combination. T2D incidence was similar across intervention centres, irrespective of attrition. Significantly fewer participants achieved normoglycaemia in the HP compared with the MP group (P < .0001). At 3 years, normoglycaemia was lowest in HP-HI (11.9%) compared with the other three groups (20.0%-21.0%, P < .05). There were no group differences in body weight change (-11% after 8-week weight reduction; -5% after 3-year weight maintenance) or in other secondary outcomes. CONCLUSIONS: Three-year incidence of T2D was much lower than predicted and did not differ between diets, PA or their combination. Maintaining the target intakes of protein and GI over 3 years was difficult, but the overall protocol combining weight loss, healthy eating and PA was successful in markedly reducing the risk of T2D. This is an important clinically relevant outcome.