HE101 Lecture Notes - Lecture 5: Underweight, Normative Social Influence, Dental Caries
Document Summary
Body mass index (bmi) relative weight for height: weight (kg)/height(m2) Bmi is a crude measure: doesn"t account for differences in body composition. Obesity: excessive body fat: associated with health risk. Visceral (abdominal) fat is associated with many diseases. Waist circumference: surrogate measure of abdominal body fat. Women < 88cm (35 ), men < 102cm (40 ) Skinfolds: measure thickness of subcutaneous adipose tissue. Can estimate % body fat using predictive equations. Bioelectrical impedance analysis (bia: weak electrical current passed through body. Shocked in one leg, calculates time it takes for the shock to go down the opposite leg. Leaner individuals circulate electricity better than others. Densitometry: based on body density and water/air displacement. Dual energy x-ray absorptiometry (dxa: small x-ray beam passed over body. Measures absorption in bone mineral and soft tissue. Ct/mri: computed tomography / magnetic resonance imaging. Precise images body composition at tissue/organ level. Important risk factor for many chronic diseases: cvd, stroke, type 2 diabetes, cancers.
