BERLIN — A 2-month weight loss regimen using meal substitutes followed by long-term weight maintenance through diet and exercise may be an optimal approach to preventing type 2 diabetes through lifestyle, new data suggest.

Main results from the Prevention of Diabetes Through Lifestyle Intervention and Population Studies in Europe and Around the World (PREVIEW) study were presented October 5 here at the European Association for the Study of Diabetes (EASD) 2018 Annual Meeting.

PREVIEW, which enrolled 2326 adults with prediabetes in Denmark, Finland, United Kingdom, the Netherlands, Spain, Bulgaria, Australia, and New Zealand, is the largest multinational trial to date to investigate the prevention of type 2 diabetes through lifestyle in adults with prediabetes. The participants were 25 to 70 years old, with a mean age of 52 years, a mean weight of 100 kg (220 lb), and a mean BMI of 35 kg/m2. Most were white (88%), and about two-thirds were women.

Previous large diabetes prevention trials such as the Finnish Diabetes Prevention Study (DPS) and US-based Diabetes Prevention Program (DPP) used uniform lifestyle interventions applied across study periods.

In contrast, PREVIEW investigated the effect of an initial 2-month intensive weight loss program using low-calorie meal substitutes (Cambridge Weight Plan), followed by randomization of participants who had lost at least 8% of their body weight to one of four maintenance interventions for 3 years.

The interventions were a high-protein (25% of energy), low-glycemic index (< 50) diet or a moderate protein (15%), moderate glycemic index (> 56) index diet combined with either moderate or high-intensity physical activity (75 vs 150 minutes/week, respectively).

After the initial 2 months, 79% (1854) of adults had lost at least 8% of their body weight and moved to the randomized maintenance phase, as previously reported by Medscape Medical News.

At EASD, the investigators reported that of the 962 participants who remained in the study at 3 years, 96% had not developed type 2 diabetes and 22% no longer had prediabetes, with no difference among the four intervention groups. In contrast, the proportions without diabetes at 3 years in the DPS and DPP were 91% and 86%, respectively.

Separating Initial Weight Loss Phase From Exercise: New Frame of Mind
The initial weight loss among the PREVIEW participants, an average of 10.7 kg (23.6 lb) — or about 10% of initial body weight in just 2 months — was “a very motivating thing for them…It brings them to a state where they want to start changing their lifestyle,” study coordinator Anne Raben, Ph.D., of the University of Copenhagen, Denmark, said during the 90-minute EASD session.

Coinvestigator Jennie Brand-Miller, Ph.D., of the University of Sydney, Australia, noted that during the 8 weeks on total meal replacement “the participants were pleased to hear they didn’t need to exercise, and they found the weight loss at this rate highly motivating. So when they did start the next phase, they were actually in a completely new frame of mind. They really wanted to maintain that weight loss. By separating those two phases, we think we have a strategy that is more effective.”

Brand-Miller said that the study findings changed her attitude about the use of meal replacements as a weight-loss strategy.

“If you’re like me and many of my colleagues, you may have thought it was best to lose weight with ‘real food’ because eventually, you have to eat real food. But many of us, after seeing what happened after that first 8 weeks of fast weight loss and the new psyche among our participants, would recommend the total diet replacements.”

In an interview, independent commentator Gabriele Riccardi, MD, of the Federico II University, Naples, Italy, told Medscape Medical News, “It’s an important study because it reinforces the concept that weight reduction is the cornerstone intervention to prevent type 2 diabetes.”

“What it adds to previous knowledge is that the effect is amplified when weight reduction is sustained over time.”

Riccardi noted the study also showed that the magnitude of weight loss is important as well. “After DPS and DPP, we were aiming for substantial weight reduction of about 5% — probably that’s the mean. But if you are able, as in this study, to achieve weight reduction of up to 10%, the benefits will be much greater.”

The approach of rapid short-term weight loss followed by long-term maintenance “may be a more feasible approach than being on a diet for many months, which many people find difficult,” Riccardi said.

He theorized that the lack of difference in the four intervention arms may have been because of lack of power, inadequate compliance to the diet and/or the exercise components, or a lack of significant differences among the specific metabolic effects of diet composition or physical activity intensity.

In any case, he said, “diet composition is not highly relevant in relation to a magnitude of weight loss, prevention of type 2 diabetes, and glucose and insulin metabolism.”

Riccardi did note that the relatively low retention rate — only 41% of participants remained in PREVIEW until the end compared with 92% in the DPS — was a limitation.

“Nevertheless, among those who completed the study, the results were remarkable,” he said.

The study received grants from the EU Seventh Framework Program, the New Zealand Health Research Council, and NHMRC-EU collaborative grant, Australia. All meals were provided by the Cambridge Weight Plan, United Kingdom. Raben and Brand-Miller have reported no further disclosures. Riccardi is an advisory board member of the Barilla Foundation for Food and Nutrition and a member of the Nutrition Foundation of Italy, an independent body subsidized by the food industry.

European Association for the Study of Diabetes (EASD) 2018 Annual Meeting; October 5, 2018; Berlin, Germany.