Chapter 7 Energy Balance and Weight Control Energy Balance o 68 of adults are overweight 50 of adults are obese o Red flags 10 pounds of weight gain 2 inch in waist circumference o Energy balance equal energy in food intake and energy out metabolism digestion absorption transport of nutrients physical activity Positive energy input energy output pregnancy infants children weight gain 3500cal 1lb Negative energy input energy output weight loss 3500 cal 1 pound o Energy Intake need to be defensive eaters Bomb Calorimeter measures amount of calories from carbohydrate fat protein and alcohol burn food raise temperature of water round up o Energy Output basal metabolism physical activity increase energy expenditure burn thermogenesis energy expended during fidgeting shivering thermic effect of food TEF Thermogenesis increase in non voluntary physical activity triggered by cold conditions or overeating increases sympathetic nervous system activity include shivering muscle tone body posture fidgeting Brown Adipose Tissue small amounts 5 in infants brown because rich blood flow release some energy from nutrients into environment as heat Thermic Effect of Food energy used to digest absorb metabolize nutrients 5 10 of total calories sales tax highest to lowest protein 20 30 alcohol 20 carbs 5 10 fat 0 3 o Basal Metabolism basal metabolic rate minimum amount of calories expending in fasting state 12 hours to keep a resting awake body alive 60 70 of total energy use in sedentary person Involves heart beat respiration and body temperature Doesn t involve physical activity digestion absorption nutrient processing Increase BMR greater lean body mass larger surface area per volume male gender body temperature fever cold environment conditions thyroid hormones nervous system activity release of norepinephrine pregnancy caffeine and tobacco use being younger 1kcal minute o Resting Metabolism resting metabolic rate 6 higher than BMR Determination of Energy Needs o Direct calorimetry measures heat output expensive and complex o Indirect calorimetry measures amount of oxygen consumed related to energy expended most common o EER estimated energy requirement Calculate for women EER 354 6 91 x AGE PA x 9 36 x WT Calculate for men EER 662 9 53 x AGE PA x 15 91 x WT PA 1 00 sedentary 1 11 1 12 low activity 1 25 1 27 active 1 48 1 45 726 x HT 539 6 x HT very active WT kilograms pounds 2 2 HT meters inches 39 4 Healthy Weight o Indications of unhealthy weight hypertensions high LDL obesity cardiovascular disease cancer high blood glucose fat o BMI unit 6 7 pounds o BMI body mass index not used for pregnant women children older people athletes Underweight 18 5 healthy 18 5 24 9 overweight 25 29 9 obese 30 39 9 severe obese 40 BMI body weight kilograms height 2 meters Excess Body Fat o Excess body fat healthy women 21 25 healthy men 8 24 o Measuring Body Fat Underwater weighing very accurate fat is less dense than lean tissue fat floats Air Displacement determines body volume in sealed chamber 495 body density 450 Skinfold measurement anthropometric Bioelectrical impedance low energy electrical current to from body adipose tissue resists electrical flow DEXA dual energy x ray absorptiometry most accurate but expensive separates body weight into fat fat free tissue and bone mineral TOBEC measure total body electrical conductance in electromagnetic Near infrared reactance inexpensive but less accurate measures bicep field o Health problems Surgical risks increased anesthesia increased risk of infection pulmonary disease sleep disorders type 2 diabetes hypertension cardiovascular disease high LDL low HDL bones and joint disorders gallstones skin disorders cancers menstrual irregularities vision problems premature death infections organ damage erectile dysfunction Upper body obesity cardiovascular disease hypertension type 2 diabetes fat goes directly to liver promotes inflammation smokers o Body Fat Distribution Nature vs Nurture Treatment of Overweight alcoholics men apple shape measure waist circumference 40 men and 35 women Lower body obesity resists being shed common in women because estrogen progesterone o Increase body fat age menopause female positive energy balance excess calorie intake low physical activity low BMR low TEF increased hunger sensations high fat low lean muscle race socially acceptable medications childbearing social behavioral factors low socioeconomic status overweight friends unhealthy meals limited fresh fruits excessive TV not smoking no sleep stress o Genes account for 70 of weight differences body type Thrifty metabolism gene more fat storage to protect against famine o Set Point theory humans genetically predetermined body fat content hypothalamus tries to keep body fat constant leptin assists in weight regulation o Female obesity rooted in childhood obesity o Male obesity appears after age 30 o Long term lifestyle changes not quick fad diets o Rate of loss slow steady 1 pound week maintenance after 10 lost o Flexibility adapts to individual habits tastes activities o Intake nutrient needs common foods fortified balanced o Behavior modification modify eating behaviors Chain braking breaking link between behaviors Stimulus control alter environment to minimize stimuli Cognitive restructuring change frame of mind regarding eating walk when stressed instead of eating Contingency management form plan of action resist pressure of eating at parties Self monitoring track foods conditions of eating know habits Weight maintenance prevent relapse social support o Overall health physical activity sleep less stress see physician dietitian o Physical Activity add weight resistance lean body uses fat bone health high metabolism 60 90 minutes day 150minutes a week o Deficit of 3500 calories to lose 1 pound o Diet Drugs Amphetamine decrease appetite prolong epinephrine in brain dependency Sibutramine enhance norepinephrine serotonin decrease appetite Orlistat inhibits digestion reduce fat absorption Alli is OTC Treatment of Obesity o Very low calorie diets 400 800cal per day low carbs high protein cause ketosis lose 3 4 pounds a week health risks cardiac problems gallstones o Bariatric surgery severe obesity Adjustable gastric banding lap band reduced esophagus opening decreases amount of food eaten band can be inflated deflated Gastroplasty stomach stapling reduce stomach capacity to 30milliliters improves overall health earlier satiety o Criteria BMI 35 40 obese for 5 years not alcoholic must
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