Seasonal Body Weight Dynamics in Healthy People: A Meta-Analysis

Abstract

Most mammalian species are known to accumulate body fat in the summer. Since the average modern human actively uses artificial lighting, heating, air conditioning and usually does not experience periods of lack of food, seasonal adaptation strategies of people can differ significantly from other mammals. The purpose of this meta-analysis is to study the seasonal dynamics of body weight in healthy adults in regions with different types of climate. We carried out a meta-analysis of 20 panel and 5 cross-sectional studies that reported on the seasonal dynamics of body weight variables in healthy people living in regions with different types of climate (from subarctic to tropical). According to the results of our meta-analysis, body mass index (BMI) of humans is subject to seasonal dynamics with a maximum in winter and nadir in summer. No gender and age dependence of seasonal dynamics of body weight was revealed. The geographical latitude and the amplitude of circannual fluctuations in meteorological factors did not significantly affect the seasonal dynamics of BMI. The most possible reason for the seasonal dynamics of BMI is seasonal fluctuations in physical activity, which is maximum in summer and minimum in winter.