The longer your waistline...
Although body mass index (BMI) is a popular indicator of normal, overweight, or obese, it is certainly an imperfect indicator. BMI takes into account only height and weight, but not muscle mass or weight distribution.
Scientists are now finding that waist circumference may be the best indicator of disease risk related to excess weight – waist circumference has been associated with diabetes, heart disease, inflammation, elevated cholesterol, sleep apnea, and hypertension. Waist circumference has gained interest because it is an indicator of visceral fat, believed to be more deleterious to health than subcutaneous fat. The exact mechanisms by which visceral fat confers greater risk than subcutaneous fat are still unclear, but it is known that these two types of fat have different gene expression profiles, visceral fat more frequently expressing certain substances that may contribute to chronic diseases.1,2
A new study that followed over 100,000 individuals for nine years has found that waist circumference correlates with risk of death, supporting the previous links between visceral fat and disease. When comparing waist size only, they found that very large waist circumferences – 120 cm (47 inches) for men and 102 cm (40 inches) for women – were associated with a doubling of the risk of death from all causes.
The most striking finding in this study was that increased waist circumference is an important predictor of mortality regardless of BMI. Even in those with “normal” range BMI, increased the risk of death. A 4-inch increase in waist circumference was associated with a 16% increase in mortality risk in men and 25% increase in mortality risk in women.
This means that excess fat around the waist is a significant risk – even in “normal weight” individuals.3 This data suggests that the size of one’s waist is even more important than the number on the scale.
Of course there is no way for us to control our bodies’ distribution of fat – whether our excess fat goes to our hips or around our organs – but we can control how much excess fat we have. Any and all excess fat is dangerous - it increases insulin levels and promotes inflammation, not to mention placing unnecessary demand on the heart. Focusing on nutrient density - emphasizing foods that minimize calories and maximize disease-protective nutrients – is an effective way to keep excess fat – both visceral and subcutaneous – to a minimum.
References:
1. Matsuzawa Y. Establishment of a concept of visceral fat syndrome and discovery of adiponectin. Proc Jpn Acad Ser B Phys Biol Sci. 2010;86(2):131-41.
2. Bergman RN, Kim SP, Catalano KJ, et al. Why visceral fat is bad: mechanisms of the metabolic syndrome. Obesity (Silver Spring). 2006 Feb;14 Suppl 1:16S-19S.
3. Jacobs EJ, Newton CC, Wang Y, et al. Waist circumference and all-cause mortality in a large US cohort. Arch Intern Med. 2010 Aug 9;170(15):1293-301.
