Nutrition reviews
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Review
Is a re-evaluation of WHO body mass index cut-off values needed? The case of Asians in Singapore.
This paper describes body composition and dietary intakes of the three major ethnic groups residing in Singapore and how these are related to cardiovascular risk factors in these groups. When the relationship between body mass index (BMI, kg/m2) and body fat percentage was studied, Singaporeans were found to have higher percentage of body fat compared with Caucasians with the same BMI. At BMIs that are much lower than WHO-recommended cut-off values for obesity, both the absolute and relative risks of developing cardiovascular risk factors are markedly elevated for all three ethnic groups. The excessive fat accumulation and increased risks at lower BMIs signal a need to re-examine cut-off values for obesity among Chinese, Malays, and Indians.
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Extremely unusual genetic conditions can reveal normal processes governing physiologic regulation and metabolism. Children with rare homozygous mutations in the leptin gene and complete leptin deficiency develop extreme hyperphagia and obesity soon after birth but respond with normal eating and a selective loss of excess body fat upon being given small amounts of leptin. ⋯ This demonstrates leptin's fundamental involvement in maintaining energy balance. Leptin also seems to act as a metabolic gate allowing children to enter puberty.