Assessment of Overweight and Obesity and the Need for Weight Loss Dr. David L. Gee FCSN/PE 446 Nutrition, Weight Control & Exercise

Assessment for Overweight and Obesity n 1998 NIH Clinical Guidelines for the Identification, Evaluation and Treatment of Overweight and Obesity in Adults. n Determine BMI n Determine fat distribution n Assess risk factors and presence of obesity related diseases

Body Mass Index n better correlation with mortality and health risks than weight for height –BMI = BW(kg) / HT 2 (m 2 ) –BW = 154 lbs / 2.2 lbs/kg = 70 kg –HT = 70 in x m/in = 1.78 m –BMI = 70 / = 22.1

Classification of Overweight and Obesity by BMI

Cautions n High BMI may be due to excessive lean body mass –use clinical judgement n Elevated BMI without other risk factors may indicate a healthy weight n Assess other risk factors

Distribution of Excessive Body Fat is an Important Determinant of Risk n Excessive visceral fat tissue –associated with increased health risk n Excessive subcutaneous fat tissue –less associated with increased health risk

Elevated Visceral Fat n Metabolically more active n Greater effect on visceral organs –Greater Insulin Resistance »hyperinsulinemia »impaired glucose tolerance »Type 2 diabetes –Hyperlipidemia »Hypertriglyceridemia »Hypercholesterolemia –Hypertension

Absence of an Effect of Liposuction on Insulin Action and Risk Factors for Coronary Heart Disease Klein, S. et al. N Engl J Med 2004;Volume 350: Photographs and Abdominal Magnetic Resonance Images Obtained before and after Action and Risk Factors for Coronary Heart Disease

Klein, S. et al. N Engl J Med 2004;350: Effects of Liposuction on Body Composition in Obese Women with Normal Glucose Tolerance or Type 2 Diabetes

Klein, S. et al. N Engl J Med 2004;350: Effects of Liposuction on Risk Factors for Coronary Heart Disease in Obese Women with Normal Glucose Tolerance or Type 2 Diabetes

Body Fat Distribution: other names n Android Obesity –abdominal obesity –central obesity –upper body fat –“apple shape” obesity n Gynoid Obesity –lower body obesity –“pear shaped” obesity

Assessment of Body Fat Distribution Old Method n Waist to Hip Ratio – W/H ratio n Upper Body Obesity when W/H is: –> 0.8 females –> 0.9 males

Assessment of Body Fat Distribution n 1998 NIH Guidelines n Waist Circumference –for BMI: –> 40 inches in males –> 35 inches in females –Waist circumference is measured just above the iliac crest.

Additional Risk Factors n Each additional risk factor increases chronic disease risk n hypertension (>140/90) n impaired glucose tolerance (110 – 125 mg/dl) n hypertriglyceridemia (>150mg/dl)

Additional Risk Factors n hypercholesterolemia (>240mg/dl, >160mg/dl LDL) n low HDL-C (<35mg/dl) n family history (parent/sibling) of early CHD, hpt, DM –M>55, F>65 n Age M>45 or F>55

Presence of Obesity Related Diseases n Obesity Related Diseases –Symptomatic coronary heart disease –Diabetes –Stroke or other indicators of high stroke risk n In combination (>2) with BMI > 25 establishes client at a “unhealthy weight” and weight loss is recommended

Summary of Assessment n BMI < 25 –Relative risk is low »Unless high waist circumference (see following) –Subject is at a “healthy weight” –Weight loss is unnecessary n BMI > 30 –Relative risk is high to extremely high »RR dependent on presence of other risk factors –Weight loss is recommended

Summary of Assessment n BMI = (overweight) n Or waist circumference > 35”F, 40”M n AND 2 or more risk factors n Relative risk: high to extremely high n Weight loss is recommended

Initial Weight Loss Goals n Client should attempt to lose 10% of body weight over 6 months n Example: –45 yo male, Ht=70”, BW=200lbs, mild hypertension, glucose intolerance, waist circumference = 38” –BMI = 29 –client at unhealthy weight –initial weight loss goal 20 pounds

Initial Weight Loss Goals n Reassess at 6 months n If 10% weight loss not achieved: –New strategies for weight loss –Prevent further weight gain n If 10% weight loss achieved: –risk factors normalized or no obesity related disease »focus on weight maintenance –risk factors not normalized, presence of obesity related disease with weight loss, inadequate weight loss »strategies for further weight loss »prevention of further weight gain

Treatment of Overweight n Based on overall disease risk –assessment of BMI –assessment of other risk factors (>2) –presence of obesity related disease

The realities of weight change: n Weight gain occurs when: –Positive energy balance »Energy in > energy out n Stable weight occurs when: –Energy equilibrium »Energy in = energy out n Weight loss occurs when: –Negative energy balance »Energy in < energy out n Weight loss is simple but not easy!

Treatment Affecting Energy Intake n listed from low to high risk n Healthy diet (+Behavior Modification) n Balanced hypocaloric diet (+BM) n Drugs n Very Low Calorie Diets n Gastric & Intestinal Surgery

Treatment Affecting Energy Expenditure & Losses n listed from low to high risk n Increase lifestyle activity n Aerobic exercise (BM) n Strength training (BM) n Drugs