Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial

BACKGROUND/OBJECTIVES: Short-term studies have suggested beneficial effects of a Palaeolithic-type diet (PD) on body weight and metabolic balance. We now report the long-term effects of a PD on anthropometric measurements and metabolic balance in obese postmenopausal women, in comparison with a diet according to the Nordic Nutrition Recommendations (NNR). SUBJECTS/METHODS: Seventy obese postmenopausal women (mean age 60 years, body mass index 33 kg/m(2)) were assigned to an ad libitum PD or NNR diet in a 2-year randomized controlled trial. The primary outcome was change in fat mass as measured by dual-energy X-ray absorptiometry. RESULTS: Both groups significantly decreased total fat mass at 6 months (- 6.5 and - 2.6 kg) and 24 months (- 4.6 and - 2.9 kg), with a more pronounced fat loss in the PD group at 6 months (P < 0.001) but not at 24 months (P 0.095). Waist circumference and sagittal diameter also decreased in both the groups, with a more pronounced decrease in the PD group at 6 months (- 11.1 vs - 5.8 cm, P = 0.001 and - 3.7 vs - 2.0 cm, P < 0.001, respectively). Triglyceride levels decreased significantly more at 6 and 24 months in the PD group than in the NNR group (P < 0.001 and P = 0.004). Nitrogen excretion did not differ between the groups. CONCLUSIONS: A PD has greater beneficial effects vs an NNR diet regarding fat mass, abdominal obesity and triglyceride levels in obese postmenopausal women; effects not sustained for anthropometric measurements at 24 months. Adherence to protein intake was poor in the PD group. The long-term consequences of these changes remain to be studied.