A body mass index under 16 in women is associated with anorexia in rich countries, but with malnutrition in low- and middle-income countries. It is associated with reduced life span, but the effects of energy supplementation in people who were seriously malnourished as children are uncertain. A recent cross-sectional study of over 40 countries using Demographic and Health Surveys shows a pooled incidence of extreme underweight of 1.8% (standardised for age). The prevalence is highest in India at over 6% and Bangladesh at over 3%. Rates are declining quite rapidly in these countries, but overall at a very low rate and in some countries they are actually increasing.
— Richard Lilford, CLAHRC WM Director
- Razak F, Corsi DJ, Slutsky AS, et al. Prevalence of Body Mass Index Lower Than 16 Among Women in Low- and Middle-Income Countries. JAMA. 2015; 314(20): 2164-71.