Pretreatment Fasting Plasma Glucose Modifies Dietary Weight Loss Maintenance Success: Results from a Stratified RCT.

Abstract

Levels of fasting plasma glucose (FPG) and fasting insulin (FI) were studied as diet-specific prognostic markers for successful weight loss maintenance in participants with overweight. After losing ≥ 8% of body weight, participants received one of three ad libitum diets for 6 months: (1) a moderate-fat diet high in monounsaturated fatty acids (MUFA); a low-fat, high-fiber diet (Nordic Nutrition Recommendations [NNR]); and the Average Danish Diet (ADD). Participants were categorized as having low (< 90 mg/dL) or high (90-105 mg/dL) FPG based on preintervention values. Median FI among those having high FPG was used as a cutoff for FI (FI ≤ 50 pmol/L; FI > 50 pmol/L). Participants with low FPG and randomized to MUFA, NNR, and ADD regained similarly 2.1 to 2.5 kg after 6 months. By contrast, participants with high FPG and randomized to MUFA, NNR, and ADD regained 2.73 kg (95% CI 1.33 to 4.13; P < 0.001), -0.05 kg (95% CI -1.95 to 1.86; P = 0.96), and 4.16 kg (95% CI 2.27 to 6.06; P < 0.001) after 6 months, respectively, resulting in lower weight regain on NNR compared to ADD (-4.21 kg [95% CI -6.83 to -1.59]; P = 0.002) and MUFA (95% CI -2.77 kg [-5.12 to -0.43]; P = 0.020). The addition of FI strengthened these associations. Slightly elevated pretreatment FPG determined success in dietary weight loss maintenance among overweight patients on ad libitum diets differing in macronutrient and fiber content.