Kin 110 Lecture 9 Ch. 9 Weight Control

Energy Balance and Imbalance Weight Control Overview Energy Balance What drives us to eat and participate in activity Indices for body composition assessment Fat distribution and health concerns healthful approaches to weight loss

Energy Balance Fig 9-1, p 311 Positive Energy Balance Negative Energy Balance Maintaining balance is important health goal for the prevention of many diseases Energy Intake (macromolecules) convenience energy content of a meal Calorimeter 1 kcal - energy to raise 1 kg of water 1 degree Celsius

Energy Use Basal Metabolism (BMR) 60 - 70 % of total energy used by body minimal energy needed to keep awake resting body alive varies 25-30% between people Liver, Muscle/Brain, heart, kidneys (in order of energy utilized at rest) ~1 kcal/Kg/hour, influenced by: lean body mass and surface area, Age, (declines 2% per decade) nervous and hormonal activity, nutritional state, pregnancy caffeine and tobacco use low energy intake - decrease BMR

Energy Use Physical Activity (variable) can increase energy expenditure 25-40 % many choices available : take stairs, walk to corner store, *increase movement* Thermic effect of food (5-10 %) of total intake digestion, absorption, process

Energy Use Adaptive Thermogenesis (7%) overfeeding and shivering brown adipose tissue Measurement of Energy Use Calorimeter direct / indirect Estimates by weight, degree of physical activity and age

Estimating Energy Needs Sedentary - 20 kcal/Kg Light Activity - 30 kcal/Kg Heavy Activity - 45 kcal/Kg Estimates per day 1600 kcal/day sedentary women, older adults 2200 kcal/day active women, men 2800 kcal/day v. active women, active men,

Food Intake Hunger - physiological drive to eat controlled by internal body mechanisms Appetite - psychological drive to eat, external stimulus Satiety - state in which there is no longer the desire to eat

Estimating Healthy Weight Most are based on large population data, general guides not intended for individual application Family History of obesity related conditions is very important High BP, LDL, Glucose, obesity, heart disease, cancer Important to make individual estimate of healthy weight what weight you maintained as an adult for one year without significant hunger Be realistic healthy lifestyle is most important

Healthy Weight Body Mass Index (BMI) Table 9-1, p. 318 body weight/height*height health risk with BMI over 25 over fat or overweight??? Metropolitan Life Tables longevity not health, limited population inclusion

Energy Imbalance Energy intake exceeds output can lead to obesity Obesity - excess body fat BMI over 30, weighing 20 % more that healthy weight Health problems Table 9-2, p.319 Over Fat males 25 %, females 30-35% BMI over 40 sever health risk Underwater weighing,Skin Folds, Bio-electrical impedance

Fat Distribution Fig 9-7, p 322 Upper body obesity heart disease, high blood pressure, diabetes testosterone and alcohol lower body obesity requires about 20 lbs more for same health risk 90 % are mildly obese in USA juvenile onset, increased risk 10 % loss for “healthier weight”

Why ?? Many factors both genetic and psychological are influential Identical twins genes determine metabolic rates and brain chemistry Body Types ectomorph, mesomorph, endomorph differences in met. , surface area “Thrifty metabolism”

Environmental Influence Family eating patterns or genetics ? Little change in gene pool, but increase in obesity Table 9-3, p. 326

Treatment of Obesity Number 2 health risk in US after smoking chronic disease treatment is long term lifestyle change as with diabetes and high BP, need to have healthy active living with appropriate dietary modifications

5 Principles of Treatment Goals of dieting misdirected be realistic, most under BMI of 25 focus on healthy active lifestyle and maintenance of body weight Body defends itself against weight loss basal metabolism drops increased efficiency of fat storage Weight Cycling is Common 5% maintain loss, others gain more, increased health risk

Principles Weight gain in adulthood is common Focus on changing Body Composition loss should be from adipose not lean tissue rapid loss is fluid and lean mass only highly motivated should attempt weight loss begin with maintenance, and awareness of eating habits and physical activity patterns

Weight Loss Guidelines Table 9-4, p 331 Control energy intake, increase expenditure, acknowledge that lifelong change is necessary Rate of Loss slow weight loss 1-2 Lb per week maintenance for a few months following 10 % reduction Flexibility participate in normal activities Individual taste and habits

Weight loss Guidelines Intake meet nutritional needs minimum 1200-1500 kcal /day reduce hunger and fatigue choose common foods Behavior Modification lifetime focus to maintenance of healthy lifestyle changes are reasonable Overall Health Should consult physician if : existing health problems, (over 35) or plan to lose weight very quickly regular activity, rest, stress reduction address underlying psychological issues

Controlling Intake Estimate requirements and reduce by ~ 400 kcal / week count fat (g) not entire diet focus on naturally low fat foods rather than fat reduced use exchange system (Appendix c) reduce fat but increase bulk complex carbohydrates, fiber stick to food guide, reduce high fat foods Table 9-5, p 333

Physical Activity Regular activity has many benefits 200 kcal expenditure walking for 1 hour cycling for 30 min swimming for 20 min running for 15 min Lifestyle change - activity habits and daily routine quick walks, stairs, fidgeting Table 9-6,. P 334

Behavior Modification Lifestyle changes food intake and activity Chain Breaking breaking link between behaviors that encourage overeating/inactivity Stimulus control altering environment Cognitive restructuring changing frame of mind regarding eating

Behavior Modification Contingency Management forming plans of action to respond to potential overeating situations Self Monitoring tracking of foods and conditions affecting choices Table 9-7, p. 336 lists many helpful behaviors Prevent lapse, relapse positive framing, social support