contemporary issues in nutrition spring 2022 final exam study guide

contemporary issues in nutrition spring 2022 final exam study guide what are the differences between overweight, underweight, and obesity? overweight: weight between 10% and 20% above the desirable weight for height, or a BMI of 25.0 through 29.9 obesity: weight of 20% or more above the desirable weight for height, or a BMI of 30 or greater underweight: weight 10% or more below the desirable weight for height, or a BMI of less than 18.5 what are the problems associated with overweight, underweight, and obesity? underweight: minimal body fat stores, decreased energy reserves during times of physiological stress or injury, menstrual irregularity, infertility, osteoporosis obesity: abdominal hernias, certain cancers (colon, rectal, prostate, breast, uterus, cervical, ovarian), complications during pregnancy, complications during surgical procedures, lower longevity, lower quality of life, depression, type 2 diabetes, fertility problems, gallbladder and liver disease, heart disease, higher blood cholesterol levels, hypertension, osteoarthritis, and respiratory problems how do you calculate body mass index(BMI)? (weight in lbs / (height in in)^2) x 703 weight in kg/height in m what are the clinical guidelines for BMI? underweight = 18.5 normal = 18.5-24.9 overweight = 25-29.9 obese = 30-39.9 severely obese = 40 how does body fat distribution play a role in risk for disease? central obesity has higher disease risk how to calculate waist-to-hip ratios? ?? what are the different ways to measure body fat and how do they work? hydrostatic weighing: the less a person weighs underwater compared to the person's out-of-water weight, the greater the proportion of body fat, fat is less dense than lean tissue skinfold test: thickness of a fold of skin is measured using a caliper, back of arm, below shoulder bioelectrical impedance: measures how quickly electrical current is conducted through the body, estimates the amount of: body water, non-fat components of the body, and degree of body fat how do you use waist circumference, waist-to-hip ratios, and total body fat percentage to determine disease risk? waist for men 40 waist for women 35 waist to hip ratio men 1.0 waist to hip ratio women 0.8 total body fat % men 25% total body fat % women 33% how many calories make up 1 lb of fat? 3500 name and describe the 3 components of energy expenditure. BMR (60-65%): rate body expends energy to support vital functions at rest: heart beat, breathing, blood pressure. does not include voluntary activities physical activity (25-35%): most variable part of energy expenditure equation, varies according to body size, type of activity, volume/intensity of activity, most effective way to increase "energy out" thermic effect of food (5-10%): production of heat that occurs after eating, contributes to a rise in metabolic rate, supports ingestion, digestion absorption, transport of food, argument for frequent meals/snacks to increase thermic effect of food what factors increase BMR? caffeine, fever, growth, height, high thyroid hormone, male gender, muscle mass, smoking, stress what factors decrease BMR? age, low thyroid hormone, reduced energy intake(fasting, starvation, low calorie diet), sleep describe the 2 causes of obesity related to genetics (as discussed in lecture notes). ob gene: - produces a hormone (leptin) that tells the body to stop eating - fat stores up: higher leptin(lower appetite, higher energy expenditure) - fat stores down: lower leptin (higher appetite, lower energy expenditure) - overweight: ? defective ob gene (lower leptin production) or unresponsive to leptin fat cell theory: - overweight child has higher # of fat cells - weight loss in adulthood only decreases size of fat cells, not # of fat cells - fat cells have enzyme LPL which enables cells to store body fat, the more LPL, the more the body can pull triglycerides into fat cells for storage what are vitamins? potent, essential compounds that perform various bodily functions that promote growth and reproduction in addition to maintenance of health organic (contain carbon) do not provide calories (energy) what is the difference between fat soluble and water-soluble vitamins? water soluble - b vitamins and vitamin C - found in watery components of food - fragile in foods, can be washed out or destroyed during food storage, processing, and preparation - body excretes excess if blood levels rise too high, low risk of toxicity - no storage site in the body, daily intake recommended and deficiency symptoms appear quickly fat soluble - a, d, e, k - found in fats and oils of foods - stable in foods - stored on the liver and body fats - regular intake recommended - megadoses can build up toxic levels ( dose of ten or more times the amount normally recommended) - deficiency symptoms develop slowly folate solubility water folate function coenzyme for the synthesis of DNA and formation of red blood cells folate deficiency anemia: blood is unable to deliver oxygen to the cells of the body neural tube defects: malformations of the brain and or spinal cord during embryonic development - spina bifida: incomplete closing of bony casing around the spinal cord, leads to partial paralysis - anencephaly: major parts of the human brain are missing folate toxicity n/a folate food sources fresh green, leafy vegetables, legumes and seeds, enriched foods (due to enrichment act) b12 solubility water b12 function important in the protection of nerve fibers works closely with folate to produce red blood cells b12 deficiency nerve paralysis and damage anemia (at risk for deficiency: vegetarians and those who lack intrinsic factor (compound in the stomach necessary for b12 absorption)) b12 toxicity n/a b12 food sources animal foods, milk, meat, cheese and eggs vitamin c solubility water vitamin c function required for production of collagen (protein foundation material for bones, teeth, skin, tendons) antioxidant (prevents damage to the body as a result of chemical reactions) vitamin c deficiency unlikely to occur, except in infants who are not given a source of vitamin C, or in children or elderly who do not eat enough fruits and vegetables vitamin c toxicity n/a vitamin c food sources oranges, citrus fruits, broccoli, cantaloupe, strawberries vitamin A solubility fat vitamin a functions maintain epithelial tissues (cells that form the outer surface of the body and line the body cavities and principal passageways) production of sperm, normal development of fetuses, immune response, hearing, taste, and growth vitamin a deficiency night blindness: slow recovery of vision after exposure to bright light, need vitamin A to reform a protein that is needed for vision (deficiencies are rare because the body can store 1 year worth of vitamin A in the liver) vitamin A toxicity joint pain, dryness of skin, hair loss, irritability, fatigue, headaches, weakness, nausea, liver damage vitamin A food sources