BASAL-METABOLISM OF WEIGHT-STABLE CHRONICALLY UNDERNOURISHED MEN AND WOMEN - LACK OF METABOLIC ADAPTATION AND ETHNIC-DIFFERENCES

The purpose of this study was to investigate whether weight-stable chr onically energy-deficient subjects exhibit evidence of metabolic adapt ation and to establish whether international predictive equations over estimate the basal metabolic rate (BMR) of tropical populations. BMR, body weight, height, and fat-free mass (FFM) by underwater weighing we re measured in healthy, physically active urban dwellers of low socioe conomic status (178 men and women aged 22-38 y) in Bangalore, Southern India. Subjects were selected on the basis of body mass index (BMI; i n kg/m(2)) and classified in three groups: severely undernourished (BM I < 17.0; n = 30 men, n = 25 women), marginally undernourished (BMI = 17.0-18.5; n = 31 men, n = 30 women), and well nourished (BMI > 18.5; n = 27 men, n = 35 women). The BMR of the well-nourished group, expres sed in absolute terms (6.20 and 5.18 MJ/d for men and women, respectiv ely), was significantly higher (P < 0.000) than that of the severely u ndernourished group (5.72 and 4.64 MJ/d for men and women, respectivel y). Normalizing BMR for either body weight or FFM by analysis of covar iance abolished all differences. The mean BMR of the low-BMI study gro up was substantially higher (11-14%) than reported previously for unde rnourished Indian adults. The BMR of both men and women, regardless of their nutritional status, was accurately estimated by age-and sex-spe cific FAO/WHO/UNU equations. These findings suggest the absence of an enhanced metabolic response in weight-stable chronically undernourishe d adults. This is in contrast with earlier reports, and supports more recent views. The study also provides evidence of the absence of ethni c-specific energy turnover in Indians.