NUTR 251 Exam 3 Study Questions Energy Balance and Body Composition Chapter 8 1 Define energy balance What would be the result of positive energy balance Negative energy balance What does the body use for energy during a state of negative energy balance 1 Energy Balance is when the body weight is stable when energy consumed is equal to energy expended Energy in Energy out 2 A positive energy balance results in the storage of excess energy as adipose tissue fat You would gain weight be over consuming and consuming more calories than the body needs 3 A negative energy balance results in the use of stored energy from glycogen fat and muscle You would be losing weight fasting 4 The body uses glycogen fat and muscle 2 If Matt drank 2 beers equal to 240 kcals every day in addition to the kcals necessary to maintain body weight how much weight would he gain in two weeks Hint How many Calories kcals are equivalent to one pound of adipose tissue fat tissue 1 3500 kcal 1 pound of body weight 14 days 240 3360 He would gain 96 of a pound so basically one pound 3 What does a bomb calorimeter measure 1 Direct calorimetry using a bomb calorimeter provides a direct measure of the heat released when a food is burned its potential energy or heat of combustion A bomb calorimeter is used to determine how much energy as calories food has Measures physiological values 4 The heat generated in a bomb calorimeter for protein is 5 6 kcal g yet on a food label it tells me that protein is 4 kcal gram Why are these values different 1 The bomb measured 5 6 kcal g but we need to account for the nitrogen so we subtract 1 and then we need to subtract some for digestibility therefore we get 4 We don t use nitrogen for energy but bomb does 5 List the physiological fuel values for carbohydrate protein fat and alcohol 1 Carbohydrate 4 kcal g 2 Fat 9kcal g 3 Protein 4kcal g 4 Alcohol 7kcal g 6 You just ate 2 slices of a medium pizza for lunch Here is the nutrient analysis 21 g of protein 75 g of carbohydrates 18 g of fat and 4 g of fiber How many kcals is in this meal Calculate the percent kcals coming from fat 1 21x4 75x4 18x9 546 18x9 162 then 162 546 29 7 7 Briefly what is the difference between hunger satiation satiety and appetite Does the phrase feeling fuller for longer refer to satiety or satiation 1 Hunger signals a physiological need for food 2 Appetite influences the amount of food you consume and is affected by a multitude of factors i e sight of aroma of food emotions routines stress illness unfamiliarity of food Appetite is independent of true physiological signals of hunger and fullness 3 Satiation you stop eating after a meal because of satiation due to signals from your stomach and hormone changes as you fill up 4 Satiety occurs after a meal due to feelings of fullness and satisfaction resulting in you not eating for a while after we eat in between meals when we aren t eating 5 Feeling fuller for longer 8 Comment on the effects of nutrient composition of a meal on satiation and satiety Define low energy density Explain the difference between dietary fat having a low satiation in the stomach verses fat producing satiety signals when in the small intestine hint think about CCK 1 Protein is most satiating so as part of a meal will help in feeling full High fiber foods carbs are satiating because they fill the stomach and slow absorption They enhance satiety to feel full low in calories good strategy when losing weight Fat in a meal results in little satiation because of its high energy density high kcals gram Produces strong satiety signals once it enters the intestine Best effect use all 3 2 Energy density is the measure of energy a food provides relative to the amount of food kcalories per gram Fruit is low ed 3 The hypothalamus is a small region in the brain that coordinates input from the nervous system and hormonal system indicating hunger satiation and satiety CCK GI hormone stimulates the release of bile which leads to digestion of fats 4 Take in fat causes increase in CCK in small intestine which slows gastric emptying so you feel fuller longer and that s what happens with fat 9 There are many chemicals and hormones that affect the brain and levels of hunger and satiety Describe the action of neuropeptide Y and cholecystokinin CCK 1 Neuropeptide Y chemical affects brain causes carbohydrate cravings 1 Released from hypothalamus and increases hormones for intake of food 2 CCK GI hormone stimulates release of bile leads to diegestion slow motility of GI tract fat takes longer to digest compared to carbs it enhances satiety 1 Hypothalamus and causes food to stay in you longer thus decreases food intake 10 You expend energy ie Body uses food for fuel in three categories List these categories and define them For the average semi sedentary American what category is responsible for the most calorie expenditure What percentage does BMR account for 1 BMR 60 65 energy required to maintain life when the body is at complete rest and fasting for 12 hours Most calorie expenditure in a semi sedentary American 2 Thermic Effect of Food 10 energy to process food digestion and absorption 3 Physical activity variable energy for voluntary movement of skeletal muscles 25 35 11 What factors or characteristics can raise basal metabolic rate BMR and what factors can lower basal metabolic rate 1 Raise body composition more lean body mass higher BMR Gender male hormones lead to higher BMR than female hormones Fever Environmental temperature both heat and cold raise BMR Hormones more males than females Smoking stresses caffeine 2 Lowers Age lowers as we age Fasting starvation or a low calorie diet hormones malnutrition body composition if high fat mass and BMR is lowest when sleeping 12 What variables are accounted for in the DRI equation for calculating Total Energy Expenditure this is called Estimated Energy Requirement in the text 1 Age physical activity weight height gender 13 Sarah s BMI is 21 2 and Sonia s BMI is 28 9 Would they be considered underweight healthy weight overweight or obese List these cutoffs 1 Sarah is a healthy weight Sonia is overweight 2 Underweight BMI 18 5 Healthy 18 5 to 24 9 Overweight 25 to 29 9 Obese or equal to 30 14 What are two other criteria besides BMI which should be used to determine healthy body status in an individual Why is BMI not a perfect indicator of health risks Some people need more body fat explain 1 Have a body fat distribution that minimizes risk for disease apple vs pear