About this Research Topic
Current international recommendations for preventing and treating diabetes recommend moderate protein, higher carbohydrate diets. However, in the DIOGENES and other studies, higher protein intake and lower glycemic index were associated with improved weight loss maintenance. Furthermore, the role of different intensities and duration of physical activity for weight maintenance and prevention of diabetes is still not clear. PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World, www.preview.ning.com) was designed as a world-wide, multicentre project funded by the European Union (2013-2018) to determine the role of protein, dietary glycemic index and physical activity in the prevention of type 2 diabetes. PREVIEW included a 3-year multicentre trial in over 2000 overweight and obese individuals at high risk of developing diabetes. In addition, the same questions were addressed using longitudinal cohort studies in ~170,000 subjects in Europe, Canada and New Zealand.
The overall goal of the PREVIEW project was to increase our understanding of how diet composition and intensity of physical activity affect weight loss maintenance and the development of type 2 diabetes. Furthermore, the role of sleeping pattern, habitual stress, sociological and behavioral factors in influencing these outcomes was also investigated. In the randomized controlled trial, we recruited >2000 overweight, pre-diabetic adults, characterized by impaired fasting glucose and/or impaired glucose tolerance, who completed an 8-week period of rapid weight loss. In the following weight loss maintenance phase, participants were randomized to either a high-protein, lower carbohydrate, lower glycemic index diet or a moderate protein, higher carbohydrate, higher glycemic index diet. Within each diet group, they were further randomized to a moderate-intensity physical activity (150 mins/week) or a high-intensity exercise program (75 mins/week). Our primary hypothesis is that a higher protein, lower carbohydrate/low GI diet will be superior for prevention of diabetes in high risk individuals compared with a moderate protein, moderate-GI diet. Moreover, we also propose that high-intensity physical activity will be superior compared to moderate-intensity physical activity.
This Research Topic in Frontiers in Nutrition presents some of these findings, including data from sub-studies and individual centres. Areas to be covered include:
• Findings from the PREVIEW project exploring questions not addressed in the primary analyses, including those related to sleep, stress, socioeconomic, behavioral and other variables
• Observational analyses of the entire cohort in the randomized controlled trial, irrespective of dietary and exercise assignment
• Findings from individual centres involved in the randomized controlled trial
• Findings from the PREVIEW randomized controlled trial in children and adolescents
• Findings from populations studies in PREVIEW, including cross-sectional and longitudinal analyses of individual cohorts
The overall goal of the PREVIEW project was to increase our understanding of how diet composition and intensity of physical activity affect weight loss maintenance and the development of type 2 diabetes. Furthermore, the role of sleeping pattern, habitual stress, sociological and behavioral factors in influencing these outcomes was also investigated. In the randomized controlled trial, we recruited >2000 overweight, pre-diabetic adults, characterized by impaired fasting glucose and/or impaired glucose tolerance, who completed an 8-week period of rapid weight loss. In the following weight loss maintenance phase, participants were randomized to either a high-protein, lower carbohydrate, lower glycemic index diet or a moderate protein, higher carbohydrate, higher glycemic index diet. Within each diet group, they were further randomized to a moderate-intensity physical activity (150 mins/week) or a high-intensity exercise program (75 mins/week). Our primary hypothesis is that a higher protein, lower carbohydrate/low GI diet will be superior for prevention of diabetes in high risk individuals compared with a moderate protein, moderate-GI diet. Moreover, we also propose that high-intensity physical activity will be superior compared to moderate-intensity physical activity.
This Research Topic in Frontiers in Nutrition presents some of these findings, including data from sub-studies and individual centres. Areas to be covered include:
• Findings from the PREVIEW project exploring questions not addressed in the primary analyses, including those related to sleep, stress, socioeconomic, behavioral and other variables
• Observational analyses of the entire cohort in the randomized controlled trial, irrespective of dietary and exercise assignment
• Findings from individual centres involved in the randomized controlled trial
• Findings from the PREVIEW randomized controlled trial in children and adolescents
• Findings from populations studies in PREVIEW, including cross-sectional and longitudinal analyses of individual cohorts
Keywords: Obesity, Protein, Carbohydrate, Glycemic Index, Type 2 Diabetes
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