Can a protracted stay in the tropics permanently lower basal metabolic rates of European expatriates?

The basal metabolic rate (BMR) of 57 male and female French subjects, aged between 50 to 80 years, all in good health and normally active, was measured. All subjects had been long-term residents of the humid tropics and had returned to France at least one year earlier. Two groups, individuals born in France and those born in the humid tropics, were compared to paired randomized control groups of subjects born in France who had never lived outside France. Despite important inter-individual differences, there was a general trend towards a persistent drop of the BMR in both groups of former residents in the tropics.