energy balance and healthy weight

    Cards (90)

    • Health risks from
      • Overweight
      • Underweight
    • Weight "control" MISCONCEPTIONS

      • Focus on weight
      • Focus on controlling weight
      • Focus on short-term endeavors
    • BODY COMPOSITION IS WHAT NEEDS TO BE CONTROLLED
    • Healthy Weight

      Weight at which individual: Eats nutritiously, Exercises, Is free of health problems and disease
    • BMI

      • For adults (≥ 20 years old)
      • For children and adolescents: BMI-for age and gender, Weight – height, weight-for-age and height-for-age measurements
      • Waist circumference and Waist/hip ratio: Waist/Hip ratio is calculated to measure the degree of visceral adiposity, Good marker for increased risk of chronic diseases
      • Used to evaluate health risks of obesity: Body mass index (BMI), Waist circumference, Disease risk profile
    • Body Mass Index (BMI)

      • BMI = Weight (kg) / height2 (m)
      • Underweight <18.5
      • Overweight >25.0 through 29.9
      • Obesity ≥30
      • Risks at same BMI follow racial lines: White > Black (more LBM)
    • Not everyone can match healthy weight target of BMI of 19 to 25
    • BMI Drawbacks
      • Amount or location of fat
      • Limited BMI use with: Athletes, Pregnant and lactating Women, Adults over age 65
      • Diagnosis requirements: BMI + body composition and fat distribution, Waist circumference
    • Underweight, Overweight, and Mortality
    • Causes of overweight
      • Poor diet and inactivity
      • Genetics
      • Physiological, metabolic, biochemical, and psychological factors
      • Hypothyroidism: BMR reduces, should be corrected with medication
    • Obesity itself classified as CHRONIC DISEASE
    • Obesity-related illnesses

      • Heart disease, diabetes, arthritis, cancer
      • Dying young: With extreme obesity, Obesity = smoking in risk
      • Diabetes, Central obesity, Abdominal hernias, complications in pregnancy and surgery, flat feet, gallbladder disease, gout, high blood lipids
    • Fat Distribution

      • Fat in abdominal cavity associated with greater health risks than fat in thigh, buttocks, and hip area
      • Person with pear-shaped body has lower risk for disease than someone with apple-shaped body
      • Waist-to-hip ratio is a health indicator
    • Risks from Central Obesity

      • Diabetes, Heart disease, Hypertension, Gallbladder stones, Stroke, Some types of cancer
      • Risk of ALL cause mortality is higher for visceral fat VS subcutaneous fat (abdomen, thighs, hips and legs)
    • Adipokines

      Regulate inflammatory processes, Central obesity causes a shift favoring increase in inflammation and insulin resistance of tissues
    • More Free fatty acids, Fat collects in the liver and around the heart
    • Factors affecting fat distribution - more central obesity

      • Gender: men and women after menopause
      • Moderate to High intakes of Alcohol
    • Energy budget
      Change in energy stores = energy in - energy out
    • Energy in
      Foods and beverages, For each 3500 calories you eat in excess of expenditures, you store approximately 1 pound (1lb = 450g) body fat
    • Energy out

      Varies widely, Lifestyle and metabolism
    • In some situations, positive energy balance is normal and healthy: Pregnancy, Infants and Children, Underweight Individuals
    • Past years: Availability of food (high-fat, high-sugar), Vending machines, fast-food restaurants, Super-sized portions
    • Bomb calorimeter

      Closed container surrounded by a known volume of water, Explode food pieces in a special water lined chamber and measure the heat given off from the explosion
    • Direct Calorimetry

      Measuring heat production by the body, Individual inside an insulated chamber with water pipes measuring the rise of water temperature in degrees Celsius
    • Indirect Calorimetry

      Measures the amount of expended energy based on oxygen consumption: 1 liter of O2 consumed = 5 Cal expended
    • Components of Energy Expenditure
      • Basal metabolism (BMR): Involuntary activities that are necessary to sustain life, Voluntary activities: Intentional activities done by voluntary muscles (sports/ physical activity), Thermic effect of food: About 10% of a meal's energy value
    • Thermogenesis

      Non-voluntary activity triggered by cold conditions or overeating (e.g. Shivering when cold, or fidgeting), Smallest contribution to TEE
    • Non-exercise Activity Thermogenesis (NEAT)

      Energy expended for everything we do that is not sleeping, eating or sports-like exercise, Small contribution but accumulates over time, Important for individuals with a sedentary lifestyle, NEAT increases with overfeeding and decreases with underfeeding
    • Harris Benedict Equation
      Based on sex, height, weight, and age, For males: =66.5 + 13.8 x weight (kg) + 5.0 x height (cm) - 6.8 x age (years), For females: =655 + 9.6 x weight (kg) + 1.8 x height (cm) - 4.8 x age (years)
    • TEE = BMR * PA Factor
    • Upper body fat distribution
      Increased cardiovascular, hypertension, diabetes risk, More common in men (encouraged by testosterone), Assessed by measuring Waist Circumference: >94 cm in men, >80 cm in women → Upper body obesity
    • Lower body fat distribution

      More difficult to lose than abdominal fat, More common in women (encouraged by estrogen-stores of extra energy for pregnancy/lactation)
    • Waist-to-hip ratio
      Health indicator
    • Measuring Waist Circumference
      Measurement around the point near the belly button, Healthy WC for men: < 102 cm, Healthy WC for women: < 88 cm
    • Average Body Composition of Men and Women
    • Healthy range of body fat
      Man: 18 to 21 percent, Woman: 23 to 26 percent
    • Desirable % body fat

      Men: 8-24%, Women: 21-35%
    • Percent Body Fat: American Council on Exercise Classification

      • Essential Fat: Women 10-13%, Men 2-5%
      • Athletes: Women 14-20%, Men 6-13%
      • Fitness: Women 21-24%, Men 14-17%
      • Acceptable: Women 25-31%, Men 18-24%
      • Obesity: Women ≥ 32%, Men ≥ 25%
    • Measures of Body Composition and Fat Distribution

      • Body composition, Skin fold test, Underwater weighing, Bioelectrical impedance, Dual-energy X-ray absorptiometry (DEXA)
    • Three Methods of Assessing Body Fatness
      • Skinfold measures: use of caliper to gauge thickness of a fold of skin
      • Bioelectrical impedance: method determines body fatness by measuring conductivity. Lean tissue conducts painless electric current, fat tissue does not.
      • DEXA: two low-dose x-rays that differentiate among fat-free soft tissue, fat tissue, and bone tissue with accurate measurement of total fat and distribution of fat in all but extremely obese subjects