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

Abstract

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.

Figure 1. Flow diagram of subjects participation in the trial.

Participants were prescribed to eat either a Palaeolithic type diet (PD) or a diet according to the Nordic Nutrition Recommendations (NNR).

Figure 2. The effect of diet intervention on different anthropometric measurements.

Generalized estimated equations were used, with the Palaeolithic diet group as a reference group. P-values for the diet×time interaction for fat mass <0.001, weight <0.001, waist = 0.001, and sagittal diameter < 0.001. Data are presented as mean±SE. * P<0.05, ** P<0.01, and ***P<0.001 for differences between diet groups at respective time points based on estimated marginal means. PD - Palaeolithic type diet; NNR - a diet according to Nordic Nutrition Recommendations.