This pilot study is the first to examine the impact of alternate day fasting (ADF) combined with a high protein/low carbohydrate diet on body weight and metabolic disease riskfactors in obese adults.


Obese adults (n = 10) followed an ADF diet (600 kcal fast day alternated with an ad libitum feast day; 35% protein, 22% carbohydrate, 43% fat) for 6 months. Meal replacementswere consumed on the fast and feast days, in addition to regular foods, to help attain macronutrient targets.


Body weight decreased (P < 0.001) by 8.4 ±1.7 kg (8.6 ±1.7%) after 6 months. Fat mass and visceral fat mass were reduced (P < 0.05) by 6.4 ± 1.6 kg and 0.2 ± 0.1 kg,respectively. Lean mass decreased (P ; 0.05) by 1.30.6 kg. Systolic blood pressure was reduced (P < 0.05) by 10 ± 3 mm Hg, and diastolic blood pressure was reduced (P < 0.05) by 6 ± 3 mm Hg. Fasting glucose, insulin, insulin resistance, and HbA1c remained unchanged after 6 months of diet. LDL cholesterol and triglyceride levels decreased (P < 0.001) by 10 ± 4% and 15 ± 8%, respectively, after 6 months. HDL cholesterol levels decreased by 6 ± 3% from baseline to post-treatment.


These preliminary findings suggest that ADF combined with a high protein/low carbohydrate diet is effective for lowering body weight, visceral fat mass, blood pressure, LDLcholesterol and triglyceride levels. However, this diet has no effect on glucoregulatory factors. While these preliminary findings are promising, they still require confirmation by a larger-scale clinical trial.