Seasonal changes in body weight, body mass index (BMI) and body composition of rural Beninese women.

Seasonal changes in body weight and body mass index (BMI) of two groups of rural Beninese women were investigated throughout a one-year cycle. Average body weight showed seasonal fluctuations of 1.4 kg in South Beninese women and of 3.8 kg in North Beninese women. Weight changes were reflected in changes of BMI distribution. In a sub-group of South Beninese women (n=24) body composition was estimated in a pre- and post-harvest season using D2O dilution. bio-electrical impedance (BIA). skinfold measurements. and BMI equations. Seasonal weight change in the sub-group was 0.8± 1.6 kg (p<05). Each method indicated that there was a significant change in fat-free mass (FFM) but not in fat mass from the pre-harvest to the post-harvest season. Fat mass assessed by D2O was 12.3± 3.3 kg which was significantly lower(p<01) than the assessment by the other three methods. The difference between D2O and skinfold method was 1.5± 2.1 kg. between D2O and BIA 1.8± 2.1 kg, and between D2O and BMI 2.0± 2.0 kg. It is concluded that various methods to estimate body composition are not interchangeable in field conditions.