exer exam
Specific Health Risks of Overweight and Obesity
- Coronary heart disease - Hypercholesterolemia - Hypertension - Diabetes - Premature death
Protein Guidelines
10-35% (smallest % of total calories consumed) RDA average = .8 g/kg/day RDA athlete = 1.2-1.6 g/kg/day People on low calorie diets need to consume a higher % of protein
Common Skinfold Sites
7-site procedure Chest Axilla Tricep Subscapular Abdomen Supraillium Thigh Alternative Sites (Males & Females) Triceps Abdomen Calf Kids calf and triceps
Recommendations for Fat Consumption
<10 % saturated fatty acid intake Continued reductions to 7% <300 mg/day dietary cholesterol Avoid trans fatty acids from processed foods <5-7% of energy from cholesterol-raising fats Consume 2 servings seafood/week
Underwater Weighing
A person is weighed in air and under water The difference in weight is used to assess body fatness Body fat provides more buoyancy, so a fatter person weighs less (on a relative basis) than a lean person - Muscle is like a rock (it sinks) - Fat is like Styrofoam (it floats) - body density
Regional Fat Deposition
Abdominal body fat poses greater health risks than fat stored in other areas Males store more fat centrally and have increased health risks associated with body fatness Male apple higher health risk and female pear lower health risk Males like apple
Health Risks Associated with Excessively Low Body Fatness
Anorexia Nervosa Binge-eating Bulimia (bingeing and purging) Anorexia Athletica Female Athlete Triad Muscle dysmorphia (males) Fear of obesity Purging disorder
Water Soluble Vitamins
B-1 (thiamine) B-2 (riboflavin) Niacin (nicotinic acid; B-3) Pantothenic Acid (B-5) B-6 (pyridoxine) Biotin (B-7) Folic Acid (folacin; B-9) B-12 (cobalamin) C Taken out of the body by peeing
"healthy weight range."
BMI = weight (kg) / [height (m) x height (m)] Problem: BMI does not take muscle mass into account Standards: Overweight > 25 Obesity > 30 Severe obesity > 40
Dietary Reference Intake (DRI) Values
Protein 10-35% Fat 20-35% No more than 10% saturated fat Carbohydrate 45-65% DRI Calculator Link: The USDA has a website that calculates personally determined DRI values. You enter data such as your gender, age, height, weight, and activity level and the calculator at the website and it determines your DRI values.
Mineral Guidelines
Same guidelines as vitamins PLUS... Dietary supplementation of calcium is beneficial for post-menopausal women Salt should be limited in the diet
Saturated vs unsaturated
Saturated Animal sources Solid at room temperature Unsaturated (poly- or mono-) Vegetable sources Liquid at room temperature
Other body fat assessment techniques are available.
Bioelectric impedance: Electrical conduction is different in different tissues. Muscle has water and is a good conduction. Fat has less water and is a poor conductor. It tends to overestimate %fat in lean people and underestimate %fat in fat people. Infra-Red: Absorption of light is different in different tissues. Ultrasound: Sound absorbance is different in different tissues (muscle: sounds bounces off; fat: sounds pass through). Imaging Techniques (DEXA, MRI): Considered to be highly accurate but expensive Chemical Measures: 3 methyl histidine - waste product of muscle - corr with LBM
Other Body Composition Assessments
Bioelectrical impedance Imaging techniques
Anthropometric Measurements
Body Mass Index (BMI) Waist to Hip Ratio (WHR) Circumference measures
Classes of Nutrients
Carbohydrates Fats Proteins Vitamins Minerals Water
Carbohydrate Recommendations
Choose fiber-rich fruits and vegetables Minimum of 5 servings/day Select whole grain foods when possible Choose and prepare foods and beverages with little added sugars or caloric sweeteners
Complex Carbohydrates
Complex: Pasta, rice, breads, potatoes Contribute nutrients and fiber Chains of glucose molecules Complex carbohydrates, on the other hand, contain a variety of vitamins, minerals, and fiber. Simple and complex carbohydrates are both composed of glucose or fructose molecules but they differ in how they are put together.
Understanding AND Interpreting Body Composition Measures
Component of health-related fitness and metabolic fitness, Standards have been established for healthy levels of body fatness and BMI (see next slide), and Assessing body weight too frequently can result in making false assumptions about body composition changes
Functions of Water
Comprises about 60% of body weight Chief component of blood plasma Aids in temperature regulation Lubricates joints Shock absorber in eyes, spinal cord, and amniotic sac (during pregnancy) Active participant in many chemical reactions
Fat Soluble Vitamins
Consist of vitamins A, D, E, and K Absorbed at the small intestine in the presence of bile (a fatty substance) Overdoses can be toxic (A and D) Fat soluble vitamins dissolve in the body's fat tissues. Excess amounts of fat soluble vitamins can get stored up in the tissues and lead to toxic effects.
Methods Used to Assess Body Composition
DXA Underwater weighing Bod Pod Skinfold technique BIA
Dual-Energy Absorptiometry (DXA or DEXA)
DXA estimates the body's density to determine body composition. Minimal radiation exposure (comparable to an X-ray) and the individual just lays there during the scan. "Gold Standard": Highly accurate Criterion measure that has been used to validate other, more practical measures of body composition Provides whole body measurements as well as in different parts of the body
Vitamins
Do not contain calories Organic substances that regulate numerous physiological processes Antioxidant "All-stars" Broccoli, cantaloupe, carrots, strawberries, red bell peppers, sweet potatoes, spinach Two types Fat soluble (A, D, E, K) Water soluble
Vitamin Guidelines
Eat a diet containing the recommended servings of carbohydrates, fats, and proteins Extra servings of green and yellow vegetables Extra consumption of citrus & other fruits, and other non-animal food sources high in fiber, vitamins, & minerals Consider daily multi-vitamin If you have special needs, seek medical advice
Target Zone - Body Fat Reduction
F--> Daily moderate PA; 3-6 days/wk vigorous PA I --> Slow, low-intensity that results in ≤1-2 lbs/wk of fat loss T--> 30-60 minutes 200-300 min/wk Diet Consistently and daily Modest caloric restriction Moderate meals
Role of Nutrients
Growth and development Provide energy Regulate metabolism
Influences of Nutrition
Health Appearance Behavior Mood
Iron
Important component of hemoglobin Iron deficiency is known as anemia (Symptoms: shortness of breath, fatigue)
Calcium
Important for preventing osteoporosis RDA = 800-1000 mg/day Found in dairy products and vegetables High protein diets leach calcium from bones and promote osteoporosis
Benefits of Skinfold Technique
It has the following advantages: - Fairly accurate - Easy to perform - Inexpensive
Skinfold Technique
Layers of subcutaneous fat are measured at different sites of body to estimate total body fat levels
Health Risks of Obesity
Many health problems are associated with excess levels of body fatness. The presence of excess body fat impairs the function of most systems of the body (e.g., the CV system, the pulmonary system, the skeletal system, the reproductive system, and the metabolic system). It also increases risks for a variety of diseases, including a variety of cancers.
Key Recommendations
Moderate energy intake Consume nutrient-dense foods Reduce solid fats and added sugars (SoFAS) Reduce sodium intake
My Plate vs My pyramid
My Plate replaces the graphic model of MyPyramid that was for promoting healthy eating. It was created as part of the USDA's nutrition guidelines program. It is used to convey the key nutrition principles described in the guidelines.
Minerals
No calories/provide no energy Inorganic elements found in food that are essential to life processes Calcium: Bone, muscle, nerve, blood development Iron: Necessary for blood to carry oxygen Others: Phosphorus, sodium, zinc, potassium
The Origin of Fatness
Obesity is a multifactorial disease that is influenced by both genetics and the environment Body weight is regulated and maintained through complex regulatory processes Set-point Fatness early in life leads to adult fatness Changes in basal metabolic rate can be the cause of obesity "Creeping obesity" (see next slide)
Relationship Between PA & Body Composition
PA that can be sustained for relatively long periods is considered the most effective for losing body fat Strength training can be effective in maintaining a desirable body composition Regular PA is critical for building and maintaining bone health
Populations Who May Benefit from Supplementation
Pregnant/lactating women Alcoholics Elderly Women with severe menstrual losses Individuals on VLCDs Strict vegetarians/vegans Individuals taking medications or with diseases that inhibit nutrient absorption
Low Carb Mania (What is the basis?)
Proponents of low carb diets blame carbohydrates on the obesity epidemic, but this is not well supported by research The quality of carbohydrates is the real issue and it is still wise to consume quality whole grains with adequate fiber
Simple Carbohydrates
Simple Soda, candy, sweets, fruit Individual glucose, sucrose, or fructose molecules Increase blood sugar Promote fat deposition Simple carbohydrates exist as independent glucose or fructose molecules whereas complex carbohydrates are connected in chains. Because of these differences, simple and complex carbohydrates are processed very differently by the body (discuss insulin effect from simple carbs). Simple and complex carbohydrates are both composed of glucose or fructose molecules but they differ in how they are put together. With the exception of fruit, simple carbohydrates are typically known as "empty calories" because they contain nothing but calories.
Protein
Sources of protein Animal (complete) Meats, dairy Vegetable (incomplete) Beans, nuts, legumes, grains Types of Amino Acids Nonessential (11): Can be made by body Essential (9): Must be obtained from diet Complete proteins contain all of the essential amino acids
Types of Fats
The hydrogenation process used to convert oils into solids produce trans fat, which is just as harmful as saturated fats, if not more so Trans fats are known to cause increases in LDL cholesterol and have been shown to contribute to the buildup of atherosclerotic plaque
Air displacement plethysmography (Bod Pod)
Uses the same principles as underwater weighing, but relies on air displacement to assess body composition Acceptable alternative to underwater weighing Particularly useful for special populations (e.g., obese older people, the physically challenged) - air displacement
Body Composition Assessment Implications of Results
Values are estimates (+/- 2-3% at best), measures such as BIA and skinfold have much higher error rates, particularly if performed incorrectly Values are personal and confidential Proper uses of results: Serve as baseline data for repeated testing Provide motivation for goal setting Provide awareness about health risks
Regional Fat Deposition Visceral Fat
Visceral body fat poses greater health risks because this fat is more labile and has greater access to the circulation The accumulation of visceral body fat is typical of the android (male) fat pattern Males: visceral accounts for 10-35% of total fat Females: visceral accounts for 8-13%of total fat
Water
Vital to life Drink at least 8 glasses a day Coffee, tea, and soft drinks should not be substituted for sources of key nutrients, such as milk, fruit juices, or foods rich in calcium ≤3 caffeinated beverages/day Limit sugared soft drinks If you drink alcohol, do so in moderation
The two most common types of skinfold calipers are
the Harpenden and the Lange calipers
