Effects of 6 vs 3 eucaloric meal patterns on glycaemic control and satiety in people with impaired glucose tolerance or overt type 2 diabetes: A randomized trial

Background/objectives: The study aimed to compare the effects of two eucaloric meal patterns (3 vs 6 meals/day) on glycaemic control and satiety in subjects with impaired glucose tolerance and plasma glucose (PG) levels 140–199 mg/dL at 120 min (IGT-A) or PG levels 140–199 mg/dL at 120 min and >200 mg/dL at 30/60/90 min post-oral glucose load on 75-g OGTT (IGT-B), or overt treatment-naïve type 2 diabetes (T2D). Subjects/methods: In this randomized crossover study, subjects with IGT-A (n = 15, BMI: 32.4 ± 5.2 kg/m²), IGT-B (n = 20, BMI: 32.5 ± 5 kg/m²) or T2D (n = 12, BMI: 32.2 ± 5.2 kg/m²) followed a weight-maintenance diet (45% carbohydrates, 20% proteins, 35% fats) in 3 or 6 meals/day (each intervention lasting 12 weeks). Anthropometrics, diet compliance and subjective appetite were assessed every 2 weeks. OGTT and measurements of HbA1c and plasma lipids were performed at the beginning and end of each intervention period. Results: Body weight and physical activity levels remained stable throughout the study. In T2D, HbA1c and PG at 120 min post-OGTT decreased with 6 vs 3 meals (P < 0.001 vs P = 0.02, respectively). The 6-meal intervention also improved post-OGTT hyperinsulinaemia in IGT-A subjects and hyperglycaemia in IGT-B subjects. In all three groups, subjective hunger and desire to eat were reduced with 6 vs 3 meals/day (P < 0.05). There were no differences in HOMA-IR or plasma lipids between interventions. Conclusion: Although weight loss remains the key strategy in hyperglycaemia management, dietary measures such as more frequent and smaller meals may be helpful for those not sufficiently motivated to adhere to calorie-restricted diets. Our study shows that 6 vs 3 meals a day can increase glycaemic control in obese patients with early-stage T2D, and may perhaps improve and/or stabilize postprandial glucose regulation in prediabetes subjects.