Abstract P410: Alternate Day Fasting with a High Fat Diet: Impact on Body Weight, Body Composition, and Coronary Heart Disease Risk Profile in Obese Adults

Abstract

Background: Alternate day fasting (ADF) with a low-fat (LF) diet is effective for weight loss and cardio-protection. However, the applicability of these findings is questionable as most Americans consume a high-fat (HF) diet. This study examined if these beneficial changes in weight and coronary heart disease (CHD) risk can be reproduced if a HF diet is used in place of a LF diet during ADF. Methods: Thirty-two obese subjects were randomized to an ADF-HF (45% fat) or ADF-LF diet (25% fat), which consisted of two phases: 1) a 2-week baseline weight maintenance period, and 2) an 8-week ADF weight loss period. All food was provided to subjects. Results: Body weight was reduced (P < 0.0001) by ADF-HF (5 ± 1%) and by ADF-LF (4 ± 1%). Fat mass decreased (P < 0.0001) by ADF-HF (5 ± 1 kg) and ADF-LF (4 ± 1 kg). Fat free mass remained unchanged. Waist circumference decreased (P < 0.001) by ADF-HF (7 ± 1 cm) and ADF-LF (7 ± 1 cm). LDL cholesterol and triacylglycerol concentrations were reduced (P < 0.01) by both interventions (ADF-HF: 18 ± 5%, 14 ± 5%; ADF-LF: 24 ± 3%, 14 ± 4%). The proportion of small LDL particles decreased (P < 0.05) in the ADF-HF and ADF-LF groups by 8 ± 3% and 10 ± 4%. Conclusion: Thus, an ADF-HF diet produces similar reductions in weight and CHD risk as an ADF-LF diet. These findings are important in terms of diet tolerability and long-term adherence to ADF diets.