Energy Balance and Weight Control Chapter 7 BIOL1400 Dr. Mohamad H. Termos

Introduction - Energy balance: kcalorie intake versus kcalorie output - Positive energy balance: when energy input is greater than energy output, excess calories stored  weight gain - Negative energy balance: when energy input is less than energy output  weight loss.

Energy Balance 1- Energy intake: Determining the energy content of foods 2- Energy output: - Basal metabolism: minimum energy expended in a fasting state - Factors that influence basal metabolism 1) Lean body mass 2) Amount of body surface 3) Gender 4) Body temperature 5) Thyroid hormone 6) Nervous system activity 7) Pregnancy 8) Caffeine and tobacco use

Obesity A condition in which excess body fat may put a person at health risk. A metabolic disorder that is primarily induced and sustained by an over consumption or underutilization of calorie substrate.

Causes of Obesity - Genetic background accounts for up to 70% of weight differences between people - Chances of becoming obese: 1) 10% if no obese parents 2) 40% if one obese parent 80% if two obese parent - Thrifty metabolism promotes obesity - High-fat diets and inactivity promote weight gain - Inactivity, stress, and large pregnancy weight gain are associated with obesity

Diseases linked to Obesity Diabetes Cardiovascular diseases Stroke, Arthritis, Cancer High cholesterol

Fat Distribution The area of the body where the excess body fat is located is very important to consider when assessing disease risks 1- Gynoid obesity Pear-shape obesity Common in women Fat is located around hips and thighs Lower association for disease risk. Encouraged by estrogen and progesterone

Fat Distribution 2- Android obesity Apple-shape obesity Common in men Fat is located in the abdomen Associated with heart disease, high blood pressure, and type-2 diabetes Encouraged by alcohol, testosterone, and smoking

Treatment of overweight and obesity - Long-term life style change, rather than taking medicines. Control of calorie intake Increase physical activity Eat healthy food.

Watch! Obesity in children