NFSC100Study Guide 2Questions To PonderPart 4Energy Balance and ObesityWhen fastingMobilizing storesGlycogen from liver glucose energy Glycogen stores depleted when prolonged fast breaking down body proteins and fatsEnergy BalanceChange in energy stores = energy in – energy out“Energy in” side of body’s energy budget is measured in calories taken in each day in the for of food and beverages“Energy out” 2 major components, basal metabolism and voluntary activities. 3rd component is the “thermic effect of food” can be calculated via formula or determined by observation of food maintenance at a given level of intake over time Thermic Effect of foodCost of digestion and absorption of food5-7% of total daily caloric intakeReleased as heat (not as useful for other body functions)Basal Metabolic Rate (BMR)Cost of staying aliveMeasured first thing in the morning before sitting up but after awakeningReflects differences in age and sex as well as lean body mass, stress level , body composition, growth, fever, malnutrition, height, fasting/starvation and ambient temperaturePhysical ActivityCan vary appreciably between individuals/across timeConstitutes anywhere form 35-75% or more of total energy requirementHow is Obesity Defined?BMI<18.9 underweight18.9-24.9 normal>40 morbidly obeseHealth Risks Associated with ObesityMost obese people suffer illness and obesity is considered a chronic disease300,00 people die in the US each year from obesity related diseasesHypertension, heart disease, stroke, diabetes, hernia, flat feet, sleep apnea, some cancers, high accident rate, arthritis **Greater surgical risksMeasuring Body CompositionAnthropometry (height, weight, skinfold thickness, circumference) Densitometry (under water weighing, air displacement plethsymography)Bioelectrical impedance analysis (electrical current, difference between fat mass and fat free mass)Body Fat DistributionWaist circumferenceAndroid (“beer belly” men ) – higher risk of complicationsGynoid (hips and thighs women)What causes one to be overweight?1. Physiological causes (hunger and appetite)2. Sensory influences (seek food and start meal)3. Cognitive influences (keep eating)4. posingestive influences (satiation; end meal)5. postabsorptive influence (satiaty; several hours after other activity)Metabolic Causes of ObesityHunger and satietyHormones and EnzymesGhrelinLeptin (tells you when hungry)Lipoprotein lipaseInsulin (ex. Drink coke, uptake glucose, glucose low, eat)Fat cell size/number (can increase number of fat cells throughout life)Genetic Study of Obesity One obese parent 30-70% chance of child being obeseTwins raised by different families, both likely to still be obeseGenetics VS EnviornmentGenerics have not changed in the past 30 yearsEnvironment has changed greatlyInactivity (25% of adults are sedentary)Caloric beverage consumptionPortion sizes increasedStrategies for Weight LossDiet modificationhigh carb diet but nutrient dense foodsPhysical activity increaseBehavior modification only eat at appropriate times***3500 kcal in one lb, eat 500 less kcal per day, lose one lb in one
View Full Document
Unlocking...