Body Comp Flashcards
Laboratory methods for measuring body comp
Underwater weighing
Air plethysmography (BOD POD)
DEXA*
CT/MRI
Field methods for measuring body comp
Skinfolds
Bioelectrical impedence analysis (Tanita)
Ideal weight
According to BMI
18.5-24.9 kg/m2
Ideal % body fat
Male: 10-22% (>25% is obese)
Female: 15-25% (>35% is obese)
Childhood obesity
Hyperplasia of adipocytes instead of hypertrophy
With high fat diet
After 3 weeks: hyperinsulinemia, decreased insulin sensitivity, decreased glucose uptake, hyperglycemia
Causes of obesity
Environment (decreased energy expenditure, increased energy consumption)
Appetite
Genetics
Obesity-producing environment
Bigger portion sizes, convenience food, nutrient density
Signals that influence hunger and satiety
Leptin (from adipocytes) CCK NPY Stretch Glucose/insulin
Weight loss
Most weight loss with diet and exercise
Exercise maintains FFW, increases fat utilization, decreases fat stores
What is lost with weight loss?
Week 1: 70% water, 25 % fat
Week 2-3: 70% FAT
Week 4: 85% FAT
Effective dieting
reasonable reduction in caloric intake
nutritionally balanced
losses are no more than 1-2 lb/week
Consequences of severe weight loss
Dehydration
Chronic fatigue
Female athlete triad
Little long-term success
Signs an athlete is not eating enough
Hungry and irritable, lightheaded and shaky, weight loss, excessively fatigued, amenorrhea, frequent injury or sickness, arrested growth, disordered eating
Consequences of menstrual dysfunction
No spike in estrogen
estrogen is necessary for bone health and is cardioprotective
Recommendations for female athlete triad
Focus on caloric balance
Educate on healthy weight, eating habits, cycle regularity
Promote healthy body image
Track menstrual cycle
Cholesterol lowering diet
As effective as statins in reducing LDL
BMI not accurate for…
Younger than 19 or older than 70
Women who are pregnant or breast feeding, competitive athletes, body builders, chronically ill
Regional fat distribution
Android (apple) - greater health risks
Gynoid (pear)
Waist-to-Hip standards
Men: high risk (>1), moderate (0.9-1), low risk (0.85)
Women: high risk (>0.85) moderate (0.8-0.85), low risk (<0.8)
Tanita scale (BIA)
Determines fat to lean muscle content via electrical current
Quick, easy, less prone to investigator error
Skinfold testing
Most widely used
Men: chest, abs, thigh
Women: triceps, suprailiac, thigh
Not ideal for very obese individuals
How to improve body comp
Exercise and nutrition
Combinations of 30-60 minute low to moderate aerobic activity per day
Mild caloric restriction
Resistance training 2-3x/week