Food Based Intervention Rich in Plant Components to Improve Metabolic Health in Prediabetics (FBIP) Study

The worldwide prevalence of type 2 diabetes has increased by more than two-fold over the past three decades, with ~60% of diabetics in the world currently living in Asian countries. Type 2 diabetes occurs at a younger age and at lower body mass index (BMI < 22 kg/m2) in Asians as compared other ethnic groups. Among the various evidence based approaches to diabetes prevention, diet plays one of the most important roles. In particular, food based interventions are beginning to emerge as superior strategies in the prevention of type 2 diabetes compared to nutrient based approaches. It is important of course to align food based interventions to the cultural and region specific aspects of food choice and eating behavior if such lifestyle pattern is to be implemented in a given population. To this effect, the investigators will investigate the effects of a multiple food components in combination on metabolic health outcomes, within an Asian dietary context. This proposed study will be undertaken in prediabetics who are at greater life-time risk of developing type 2 diabetes than their normoglycemic counterparts.

Based on the current evidence, the investigators will design a food based intervention consisting of a diet rich in legumes, low GI starches (such as rice, noodles),healthier vegetable oil blends (such as rice bran, peanut, sesame seed and sunflower oils) as well as certain herbs and spices. As part of this study, each volunteer will be provided with 2 of their 3 meals per day, consisting of the above mentioned foods, for a period of 16 weeks. The control group will also be provided 2 meals per day, matched for the total calorie contents. The total calorie content of each provided meal will be approximately 500 kcal for males and 400 kcal for females. The difference in the calorie contents between the genders will be made up by using prepacked snacks. There will also be further differences in the snack types between the two intervention (treatment vs control) groups. While the treatment group will consist of healthier snacks such as seeds and wholemeal crackers, the control group snack ingredients will be made from refined flour biscuits etc. The remaining foods (free choice) during the day will be monitored regularly by the study dietitian to ensure a small calorie deficit that should lead to an approximately 5% weight loss in both intervention and control groups. Therefore, while it is expected that even the control group will achieve some metabolic health benefits during this 16 week dietary intervention (indirectly due to weight loss), the investigators anticipate that the treatment group will attain greater benefits as compared to the control group, due to the differences in their food constituents. The effects of dietary interventions on metabolic health will be assessed at every 4-8 week intervals. The primary outcome measures will include several markers of glucose homeostasis (including HbA1c, fasting glucose, fasting insulin and a 2-hr oral glucose tolerance test [OGTT]). The secondary outcomes will include blood lipid profile, fructosamine, adiponectin, markers of oxidative stress and chronic inflammation.