Chapter 4 Alcohol - Energy Balance and Weight Control

Energy Balance & Weight Control 70 million adults and 12 million children as overweight or obese o o Overweight: BMI between 25 and 30 Obesity: BMI over 30 Energy Balance: relationship between energy intake and expenditure Energy equilibrium o Intake = expenditure Positive energy balance o Intake > expenditure Negative energy balance o Intake < expenditure Energy Intake: energy content of food Calculated by determining the amount of carbohydrates, protein, fat, and alcohol of food o Nutrient databases Directly measured using a bomb calorimeter 1 calorie: amount of energy to heat 1 gram of water by 1 degree Celsius Energy Expenditure: energy usage 1. Basal metabolism 2. Physical activity 3. Thermic effect of food 4. Thermogenesis Basal Metabolic Rate (BMR): minimum energy expended in fasting, resting state in warm quiet environments Fasting is not eating for 8 hours Fuel vital functions o Pumping blood o Expanding lungs o Brain function ~60% of total energy expenditure o For a sedentary person Women: 0.9 kcal/kg/hour Men: 1.0 kcal/kg/hour Resting metabolic rate (RMR) o 3-4 hour fasting period or resting (6% higher) Organ Percent of Total Energy Liver 27% Brain 19% Skeletal muscle 18% Kidney 10% Heart 7% Other 19% Factors influencing BMR o BMR can vary 25-30% among individuals o Lean body mass Higher = Higher BMR Most important factor o Body surface area Taller, larger = Higher BMR o Body temperature o Thyroid hormones Higher = Higher BMR o Nervous system activity Higher = Higher BMR o Age 1-2% decrease per decade after age 30 o Energy balance 10-20% reduction in conservation or starvation mode o Tobacco, caffeine use Increase BMR o Male gender Example calculation o BMR for Female (whose weight is: 140 lb): 140 / 2.2 = 64 kg (since 1 kg ≈ 2.2 lb) 64 x 0.9 =58 kcal/hour (A rough estimate of basal metabolic rate for women is 0.9 and for men is 1.0) Use the hourly BMR to estimate daily BMR:  58 kcal/hour x 24 hours = 1392 kcal/day  1192 – 1592 kcal/day for variation of 25 - 30 % Physical Activity 25-40% of energy expenditure Accounts for a large difference in our energy expenditure and the greatest portion of energy expenditure BMR will increase as well with increase in physical activity Will also increase muscle mass o Results increase of BMR Thermic Effect of Food (TEF): energy needed to digest, absorb, transport, store and metabolize nutrients 5-10% of daily energy intake Varies with food composition o Protein rich: 20-30% of daily energy intake (DEI) o Carbohydrate rich: 5-10% DEI o Fat rich: 0-3% DEI Large meals result in higher TEF values than the same amount of food eaten over many hours Thermogenesis: adaptive heat production Fairly small contribution to energy expenditure Nonvoluntary activities o Fidgeting o Shivering o Maintaining muscle tone Measuring Energy Expenditure Direct calorimetry: measuring amount of body heat released o Person is placed in insulated chamber, surrounded by water o Change in water temperature is measured Energy the body uses eventually leaves as heat o Too expensive and complex Indirect calorimetry: measured by collecting expired air during a specified amount of time o Predictable relationship between use of energy, oxygen, and carbon dioxide o Most commonly used o Another method- use of stable isotopes Drink of doubly labeled water 2  H2O and H2O18  Urine and blood samples analyzed  Very expensive Estimated energy requirements (EER) o Factors Height Weight Degree of physical activity Age o Equations EER  Men 19 and older EER = 662 – (9.53 x AGE) + PA (15.91 x WT + 539.6 x HT)  Women 19 and older EER = 354 – (6.91 x AGE) + PA (9.36 x WT + 726 x HT) AGE = age in years PA = physical activity level WT = Weight (kg) HT = Height (m) Mifflin- St. Jeor Equation  Another way to estimate energy needs  Based on resting metabolic rate  If RMR cannot be measured using indirect calorimetry, then this equation is the most accurate in estimating RMR  Men: RMR = (9.99 x wt) + (6.25 x ht) – (4.92 x age) + 5  Women: RMR = (9.99 x wt) + (6.25 x ht) – (4.92 x age) -161  Equation uses weight in kilograms and height in centimeters  Wt. ÷ 2.2 = kg Ht x 2.54 = cm Activity factor  Multiply the RMR by an activity factor to estimate energy requirements 1.2 = sedentary 1.375 = Lightly active (light exercise/sports 1-3 d/week 1.55 = Moderately active (moderate exercise/sports 3-5 d/wk 1.725 = Very Active (hard exercise/sports 6-7 days/week 1.9 = Extra Active (very hard exercise/sports & physical job or training Estimating Body Weight and Composition Body composition: ratio of fat to lean tissue Percent body fat Lean body mass Storage fat Subcutaneous fat Visceral fat Body weight minus body fat Muscle Bones Organ Essential fat Body Fat Levels for Optimal Health Body fat can range from 2-70% Compartment Men Women Essential fat 3% 12% Desirable fatness 8-24% 21-35% Overfat >25% >35% Women have more fat for hormones and around organs o Extremely low body fat can lead to the menstruation cycle stopping Functions of fat o Protects internal organs o Protects bones o Hormones o Cellular membrane Measuring Body Fat Content Body volume measuring o Underwater weighing, air displacement o Body density = body weight/body volume o % body fat= 495/body density - 450 Skinfold thickness o Common anthropometric method o Using calipers o Values are entered into a formula o Bioelectrical impedance o Painless, low energy electrical current o Adipose tissue resists electrical flow more than lean tissue o Not as exact Dual energy x-ray absorptiometry (DEXA) o Most exact method o Very expensive o Estimates Body fat Fat-free soft tissue Bone minerals Determining Healthy Body Weight Weight for height tables o Good estimates for populations o Don't consider body composition o Don't refer to individual's health status Would need to also consider  Amount of exercise  Lipid levels Cholesterol Triglycerides LDL HDL  Blood pressure  Food intake o Body mass index (BMI) o Equations Body weight (kg)/ height2 (m) Body weight (lb) x 703/height2 (inches) o Healthy weight: BMI 18.5-24.9 o Overweight: BMI 25-29.9 o Obese: BMI > 30 o Waist circumference o o o Indicator for visceral fat and android body shape To do so Take a tape measurement and draw it tight around the top of the iliac crest, which is the top of the hip bone Disease risk Men Low < 35.5 < 32.5 35.5-40 32.5-35 Moderate High >40 Women >35 Growth Charts for Children Ages 2-20 years Children's BMI is measured on Body Mass Index for age percentile charts Find the child's height and weight to determine BMI percentile o Where the two measurements on the chart intersect Definitions o >95th% = obese o ≤85th% and < 95th% = overweight o 5th% - 85th% = Healthy weight/Normal weight o ≤5th% = underweight http://www.cdc.gov/nccdphp/dnpa/growthcharts/resources/growthchart.pdf BMI: Standard of Bogus? Measurement for healthy weight, not body fat Not accurate for o Athletes and people with high percentage of muscle mass o Very short individuals < 5 feet o Elderly o Children May need to be adjusted based on different race/ethnic groups o BMI cut points may need to be lower for Asians East asians such as  Japanese  Chinese  Vietnamese Body Fat Distribution Affecting Health Upper body (android/apple) obesity more often associated with o Cardiovascular disease o Hypertension o Type 2 diabetes Upper body obesity encouraged by o High body testosterone levels o Diet with high glycemic load o Alcohol intake o Smoking Fat around the hips and thighs have lower risk of developing CVD, hypertension, and type 2 diabetes o Gynoid or pear shape Role of Genetics Genes account for 40-70% of weight differences in people o Twin studies o Body type o Metabolic rate o Factors affecting hunger and satiety Set point theory o Genetically predetermined body weight and body fat content o Body resists weight loss and weight gain deviating from set point o Body can establish new set points Exercise Healthy diet rich in whole grains and fiber If one parent is overweight, the child has a 40% of being overweight, and if both parents are overweight, the child has a 80% chance of being overweight Role of Environment Over the last 50 years, genes have no changed, but obesity is on the rise Environmental factors o Food availability More access to foods Low prices o Food preferences o Food marking o Social networks Friends who are all overweight tend to be in the same group o Culture Busy lives, less focus on food preparation o Education Less education/lower SEC tend to be more overweight o Lifestyle o Health concerns o Income Genetic and Environmental Synergy Factors encouraging excess fat storage o Age o Female gender o High-calorie diet o Sedentary lifestyle o Weight history o Social and behavioral factors o o o Medications Geographical location Genetic characteristics Weight Control Eating Behavior Regulation Hunger o Physiological drive Organs Hormones Hormone like factors nervous system Appetite o Psychological drive Social factors Time of day Mood Fulfilling either or both drives results in satiety Prader-Willi syndrome: child is never full/satisfied which may be caused by brain tumors, hypothyroidism, and congenital syndromes o Bariatric surgery Satiety: quality or state of being fed or gratified to or beyond capacity Fullness Hypothalamus o Communicates with endocrine and nervous system o Signals that we are full o Integrates many cues o Satiety center/feeding center Eating Behavior Regulation Feelings of satiety are elicited first by the sensory aspects of food and the knowledge that a meal has been eaten. Chewing also seems to contribute to satiety (in part linked to release of neurotransmitter histamine which affects satiety center in the brain). Next the stomach and intestines expand which further contributes to satiety. Finally, the effects of digestion, absorption, and metabolism promote satiety. The metabolism of protein may promote short-term satiety by decreasing the secretion of hormones, such as ghrelin. Leptin is a protein made by adipose tissue and functions like a hormone to reduce food intake. Several hours after eating, concentration of macronutrients in the blood begin to fall and the body starts using energy from body stores. This change causes feeling of satiety to diminish, and feeding signals begin to dominate again. Treatment of Overweight and Obesity Overweight is a disease, which needs lifelong treatment o o o o Control energy intake Energy intake needs to be equal to our energy expenditure in order to keep our weight the same To lose weight- energy intake needs to be lower than energy expenditure Adipose tissue contains about 3500 kcal/lb To lose 1 pound per week Energy intake decreased by 500 kcal/day or Activity level increased by 500 kcal/day Strategies: Less diet, more lifestyle change Smaller portions Low energy density approaches seem most successful. Bigger portions for less calories Physical activity Regular exercise to promote weight loss and to increase muscle mass All us extra calories to enjoy a treat at times Duration and regular performance Enjoyable activity Resistances training Problem behavior Large influence in our energy and physical activity Chain-breaking Eating chips while watching TV Activities associated with food Driving through fast-food on the way home from work Stimulus control Storing foods out of sight Cognitive restructuring Stress, reward eating → find different outlet Contingency management Prepare for situations triggering overeating Ex: planning on going to a Christmas party with lots of food, plan on standing away from the table or eating something small before going to the party Self-monitoring Weight-Loss Maintenance Eat low-fat, high-carbohydrate diet Eat breakfast Self-monitor weight and food intake Physical activity plan o Fit everything around exercise Fad Diets Unhealthy or unrealistic eating plans o Atkins diet, zone diet, fit for life Promise rapid weight loss Trying to sell product o Book o Membership Not designed for long term weight loss Composition of fad diets o Type of diet Carbohydrate % energy Protein % energy Fat % energy Low carbohydrate, higher protein, high fat Exs: Atkins, South Beach <20 25-30 55-65 Very high carbohydrate, moderate protein, low fat Ex: Pritkin, Dr. Ornish's >65 10-20 <10-19 DRI 45-65 10-35 20-35 Low-Carbohydrate Diets Not enough glucose leads to using glycogen storages Reduced glycogen synthesis leads to reduced amount of water in the body o 3 g of water are stored in the body with every gram of glycogen o Water loss, not fat loss Body proteins used for gluconeogensis o Typical fatty acids cannot form glucose o Lean body tissue contains 72% water Ketosis o Loss of ions Short term rapid weight loss o No advantage long term Red Flags Lists of “good” and “bad” foods Claims that sound too good to be true Recommendations made to help sell a products; often, testimonials are used Recommendations based on a single study Drug Treatment for Weight Loss Some individuals who are extremely overweight, find exercise difficult due to o Knee pain o Joint issues o Life threatening conditions that could be fatal Heart attack High blood pressure Uncontrolled diabetes Candidates o BMI > 30 o BMI 27 – 29.9 with weight-related health conditions Shown successful only in combination with life style changes Medication o Provide a sense of reduced hunger o Inhibit lipase activity in small intestine o Enhance metabolism If too much fat is consumed while on medications, extreme GI upset will occur Treatment for Severe Obesity Morbid obesity: Weighing at least 100 lb over healthy body weight o Some may not be able to walk Requires professional treatment Very-low-calorie diets o 400-800 kcal/day, 50 % carbohydrates, 50 % high quality protein o Often liquid form o 3 – 4 lb weight loss per week o Risk of heart problems and gall stones Baratric Surgery LAP-BAND o Aka laparoscopic adjustable banding Gastroplasty o Reduce stomach capacity to 30 ml (1 egg)