The effect of three different ad libitum diets for weight loss maintenance: a randomized 18-month trial

Purpose To test the effect of three diets in their ability to sustain weight loss and improve type 2 diabetes (T2D) and cardiovascular disease (CVD) risk markers after 18-month intervention. Methods Following a ≥8 % weight loss, 131 healthy, overweight/obese (BMI ± SD 31.5 ± 2.6 kg/m 2 ) men ( n = 55) and women ( n = 76) aged 28.2 ± 4.8 years were randomized to either 1. Moderate fat (40 E%) with 20 E% MUFA and low in glycemic index (GI) (MUFA, n = 54), 2. Low fat (25 E%) and medium in GI (LF, n = 51) or 3. Control (35 E% fat) and high in GI (CTR, n = 26) all with similar protein content, and all provided ad libitum. First 6-month intervention with 100 % food provision (previously reported) following 12 months of moderately intensive intervention with 20 % food provision now reported. Results Attrition rate was higher in MUFA (63 %) than in LF (37 %, P = 0.019) and CTR (42 %, P = 0.09) group. Weight regain in completers was not different between groups (mean ± SEM), MUFA 7.1 ± 2.1 % versus LF 5.6 ± 1.3 % versus CTR 7.2 ± 1.5 %, nor was body fat regain, MUFA 4.8 ± 1.0 % versus LF 4.7 ± 0.8 % versus CTR 5.7 ± 0.6 %. The MUFA group reduced LDL/HDL ratio by −0.47 ± 0.09 compared with −0.23 ± 0.11 in LF ( P