Results from the PREVention of Diabetes through Lifestyle Intervention and Population Studies in Europe and around the World (PREVIEW) study, which compared the benefits of two diet and two weight management programs, showed comparable rates of delay toward type 2 diabetes development in patients with prediabetes who had initially lost weight on a low-calorie diet. The results were presented at the Scientific Sessions on Saturday, June 8.

The PREVIEW study is the first multinational, randomized controlled diabetes prevention trial and the first to use total meal replacements. Researchers analyzed data from 2,223 adult participants at eight sites around the world.

The 36-month intervention consisted of two phases: a two-month period of rapid weight reduction on a low-calorie diet (800 kcal/day), followed by a 34-month, randomized diet and exercise phase for weight-loss maintenance that consisted of four treatment arms. Researchers compared the impact of a high-protein, low-glycemic index (GI) diet versus a moderate-protein, moderate-GI diet, both in combination with moderate- or high-intensity physical activity, on the incidence of type 2 diabetes and related clinical endpoints.

Of the 2,223 participants originally enrolled, 2,202 successfully lost 8 percent of their body weight during the weight-loss phase. In January 2019 when the study ended at 36 months, 962 remained in the study. Researchers reported 62 cases of type 2 diabetes, for a cumulative incidence rate of type 2 diabetes of 4 percent over the three years of the study. That rate was much lower than anticipated, according to PREVIEW co-principal investigator Ian MacDonald, BSc, PhD, Professor of Metabolic Physiology at the University of Nottingham, United Kingdom, who presented results from the lifestyle intervention arm of the study.

“Further work is needed to explore the reasons for such successful prevention of type 2 diabetes, but it’s almost certainly because of the large initial weight loss combined with the overall healthier lifestyle, the physical activity, the higher protein intake than any of them had to start with, and the specific behavioral modifications which were embedded into this lifestyle intervention. Those things together are likely what resulted in these outcomes,” Dr. MacDonald said. “These results suggest that the inclusion of an initial period of a low-calorie diet achieving significant weight loss, preceding a well-structured and effectively delivered weight maintenance program may be a major feature of future diabetes prevention programs.”