NUTR 202 1nd Edition Lecture 17 Ch 9 Millions of people in the US are overweight and obese 68 Adults 1 3 of children Greater risk Minorities low income southern regions Health and socio economical consequences many chronic diseases psychological problems costly and results in death Obesity represents a Global Epidemic Obesity has been shown to increase the risk of heart attack by 60 80 Over 80 of people with type 2 diabetes are obese Good news research has indicated that modest weight loss of 5 10 can reduce the risk of heart diseases and type 2 diabetes Health weight weight that minimizes health risks Not a single number It s a healthy lifestyle Weight Management Means maintaining your weight within a healthy range to reduce your risk for specific health problems Being overweight obese or underweight can be unhealthy Body mass index Relative weight for height BMI weight kg height m 2 Health related classifications Healthy weight 18 5 24 9 more than 25 is overweight and over 30 obese Body Composition is the relative amt of fat and lean body mass some fat is essential Excess fat increases risk of chronic health problems depends on location of excess fat Apple abdominal area most likely males vs Pear shape Normal levels of fat mass Men 8 19 Women 21 32 Changes occur as we age lean body mass fat mass Subcutaneous fat Adipose tissue under the skin for example in hips and legs Pear shape does not increase health risk as much as excessive visceral fat These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Visceral fat Adipose tissue around abdominal organs Apple shape central obesity More metabolically active Associated with higher disease risk Healthy Weight Rather than a single number it is a range of weight that is appropriate for your Gender height muscle mass weight you feel energetic fit Healthy weight Weight that minimizes health risk REALISTIC BMI Relative Weigh for Height Body composition Relative amounts of fat and fat free lean tissues bone muscle internal organs Visceral fat versus Subcutaneous fat Visceral fat Around organs Central Obesity Apple Shape Subcutaneous fat Below the Skin Fat Sandwich Pear Shape Assessing Weight and Body composition 1 BMI Easiest to determine if one s weight is at a healthy level but not accurate for everybody since it does not measure fat BMI classifications Learn your numbers 2 Skin fold measurements of Fat Because more than 50 of body fat is subcutaneous fat Bio electrical impedance may be preferred 3 Waist circumference Location of Fat Indicator of whether the body distribution is unhealthy Other Laboratory Measures not easily available KNOW THESE Healthy BMI Between 18 5 24 99 Healthy Fat Mass Athletes is different Men 8 19 5 13 Women 21 32 1222 Healthy Waist Circumference Men 40 inches 102 cm Women 35 inches 88 cm Energy Balance Kcal in consumption Kcal out expenditure Imbalance will result in a change in body weight Positive Energy Balance Increased Body Fat Stores Increased appetite increased energy intake increased fat synthesis Negative Energy balance Decreased Body Fat Stores Increased energy expenditure increased fat breakdown Why are we gaining weight Energy or Calorie intake energy Calories burned Eating more Hunger vs appetite Food readily available Portion sizes Inexpensive unhealthy food Advertisements fast food Moving less Less active during leisure time Kids less active Labor saving devices Body stores excess calories small amt stored as glycogen in liver and sk musc If it is too much Remainder stored as fat in adipocytes Output basal metabolism thermic effect of food and PA Review of E intake Carbohydrate 4 calories gram 45 65 0 Fat 9 calories gram 20 30 Protein 4 calories gram 10 35 Alcohol 7 calories gram Estimated energy requirement EER number of calories needed for a healthy individual to maintain his or her weight Calculated based on gender height age weight physical activity level and life stage TEE Total Energy Expenditure is sum of 1 Basal metabolism or Basal Metabolic Rate BMR 50 70 of TEE Energy required for life sustaining functions Awaked resting body no digestion don t eat for 12 hrs 2 Physical activity PA Planned exercise Non exercise activity thermogenesis NEAT Non planned exercise activities throughout the day 3 Thermic Effect of Food TEF if eat 2 000 caloires 10 will go 200 calories 10 of TEE Digestion absorption metabolism and storage of nutrients On an average person 50 70 or the majority of the total energy expenditure is for the BMR Genetics 75 Environmental Factors Lifestyle external and Hormones internal cues Genetic predisposition to be overweight BUT eat right exercise regularly healthy weight Genetic tendency to be healthy weight BUT excess calorie little no exercise Overweight Hormones internal cues Peptide YY Short term intestine satiety Ghrelin Increases Short term stomach hunger Leptin Long term adipocytes satiety ST Ghrelin released by the stomach increases hunger appetite at usual mealtimes PYY reduces hunger appetite and is released by the distended GI tract after a meal in proportion to the number of calories consumed to reduce appetite LT Reg is Leptin RECEPTORS in BRAIN Leptin is secreted in our fat tissue Healthy body fat ranges leptin sends signal to CNS you are SATISFIED Leptin Obesity eat so many CHO s that leptin becomes resistant morbidly obese wont have hormone if start to incorporate hormone control weight But if more fat tissue overproduction of leptin will become resistant and cells of CNS won t accept the signal can t control weight Factors contributing to obesity Psychological response with food eating for comfort or stress hormonal controls altered Ex reduced response to leptin genetics Asians thinner efficient at using E and storing fat lack of PA For most people a loss of 5 to 15 of body weight will significantly reduce disease risk eat less exercise more or both Traditional theory 1lb fat 3500 calories To lose a 1lb week decrease calories by 500 kcal day Go slow 1 2 2 lbs week helps ensure mostly fat loss and not lean tissue Lose too fast Yo Yo dieting Maintain weight loss by Decrease energy intake increase physical activity and modify behavior To lose weight Decrease energy or calorie intake Might need vit supplement or MD supervision Consume nutrient dense foods and reduce intake of foods that contain Added sugars Sodas fruit drinks cakes desserts candy High in fat Fried