ES 310 exam 3 body composition and weight management

Anthropometrics

- The measurement of the size, proportions, and range of motion of the human body

- height, weight, BMI, circumferences (does not measure body %)

BMI

- a measure of body weight relative to height

- weight/height^2

- lower cut point for Asians

- does not tell you about body fat %

- not accurate for all individuals (races, ethnicities)

- higher BMI = risk of diseases

underweight and normal BMI

Underweight: < 18.5 kg/m2

Normal: 18.5-24.9 kg/m2

overweight and class I obesity:

Overweight: 25.0-29.9 kg/m2

Class I Obesity: 30.0-34.9 kg/m2

class II and class III BMI

Class II Obesity: 35.0-39.9 kg/m2

Class III Obesity: ≥ 40 kg/m2

Apple-shaped fat patterning

- Dysfunctional adipocytes

- Inc. lipolysis

- Inc. macrophage - infiltration

- Inc. inflammation

- Inc. insulin resistance

- Hepatic venous drainage

pear shaped pattern

- cardioprotective

- systemic venous drainage

waist circumference

- doesn't measure body fat %

- Indicator of obesity-related health risk and better measure of visceral adiposity

- Women: > 35 in. (88 cm)

- Men: >40 in. (102 cm)

waist to hip ratio

- People less than age of 60 → > 0.95 men and > 0.86 women

- 60-69 years: >1.03 men and > 0.90 women

way to predict body fat % from circumference measurements?

- tape measure with spring loaded handle; avg of 2 measures (retest if > 5 mm apart)

- measurement sites: abdomen, arm, buttocks/hip, calf, forearm, hips/thigh, midthigh, waist

- SEE (standard error estimate) = 2.5-4% compared to hydrostatic weighing

advantages of anthropometric measurements

- Non-invasive

- Easy to understand

- Can use with extremely obese

- Good way to track progress

- Inexpensive

- Determines fat distribution

limitations of anthropometric measurements

- Not a direct measure of body comp

- Cut points may vary for different racial & ethnic subgroups

ways to measure body comp

- Hydrostatic weighing

- Skinfold measurements

- Bioelectrical impedance analysis (BIA)

-Plethysmography (BodPod)

- Dual-energy X-ray absorptiometry (DEXA)

- Acceptable ranges vary depending on age and gender

hydrostatic weighing

- a technique that uses water to determine total body volume, total body density, and percent body fat

- when a body is immersed in water, it is buoyed by a counterforce equal to the weight of the water displaced

- Bone and muscle tissue (more dense) vs fat density

= People with more bone and muscle tissue will weigh more FFM and lower body fat %

- Requires special equipment (expensive)

- direct measure of body fat %

skinfold measurements

A method to estimate body fat by measuring with calipers the thickness of a fold of skin and subcutaneous fat

Skinfold sites for men

- 7-site: chest, midaxillary, triceps, subscapular, abdomen, suprailia, thigh

- 3-site: chest, abdomen, thigh

- 3-site: Chest, triceps, subscapular

skinfold sites for women

- 7-site: chest, midaxillary, triceps, subscapular, abdomen, suprailiac, thigh

- 3-site: triceps, suprailiac, thigh

- 3-site: triceps, suprailiac, abdominal

skinfold sites

abdominal, triceps, biceps, chest/pectoral, medial calf, midaxillary, subscapular, suprailiac, thigh

skinfold procedures

1) All measurements should be made on right side with subject standing upright

2. Caliper should be placed directly on skin surface, 1 cm away from thumb and finger, perpendicular to skinfold, and halfway between the crest and the base of the fold

3) Wait 1-2 s before reading caliper

4) Take duplicate measures at each site and repeat if duplicate measurements are not within 1-2 mm

5) Rotate through measurement sites to allow time for skin to regain normal texture and thickness

skin fold advantages

Correlates fairly well with underwater weighing

DXA Less expensive

skinfold limitations

Measurement error

Poor technique, inexperienced evaluator, poor anatomical landmark identification, improper calibration

Difficult on severely lean or obese clients

Bioelectrical Impedance Analysis (BIA)

- A method of assessing body composition by running a low-level electrical current through the body

- indirect measure; fast, non-invasive and easy

- lean tissue vs fat tissue

BIA guidelines to predict BF%

- No eating and drinking within 4 hrs, no alcohol within 48 hours, no exercise within 8 hours of the test

- No diuretic meds within 7 days of the test (must be approved by physician)

- Void the bladder within 30 minutes of the test

- Avoid BIA prior to menstruation due to water retention

- Measure in a thermoneutral environment

- Use the same BIA instrument for repeat measures over time

Bod Pod

- Fast, non-invasive, does not require water immersion

- Accommodates children, older adults, obese, and disabled individuals

- Measures air displacement

- Wear minimal form fitting clothing

- No food, drink or exercise at least 3h prior

dual energy x-ray absorptiometry (DEXA)

- A highly accurate method of measuring body composition and bone mass a

- uses a small dose of ionizing radiation

- fast and non invasive

- requires special equipment and expensive

body composition norms is affected by

age, sex, race and athletic level and method

Chronic Diseases and Complications Impacted by Obesity

- Sleep apnea

- Asthma and chronic obstructive pulmonary disease

- Infertility

- Nonalcoholic fatty liver disease

- Osteoarthritis

- Stroke

- Depressions

- Cancer

- CVD

= Diabetes

1 pound body fat =

3500 kcals

Factors that affect energy balance

- RMR, NEAT

- Illness, disease

- Physical activity levels

- Training status

- Nutritional intake

- Hormonal balance and fluctuation

-Neurochemicals

- Environmental factors

- Genetics

fat mass=

body mass x (% fat/100)

FFM =

body mass - fat mass

desired BW=

desired BW= FFM/1-(desired%BF/100))

the role of exercise in weight loss

- PA alone results in minimal weight loss

- Reduced EI plus increase in EE (5-10% initial weight lost)

- Dose-response between volume of PA & weight loss

- 200-300 min/week to reduce weight regain

- Resistance training & weight loss; RT isn't solely enough to lose weight but it enhances muscular strength, physical function, improve cardiometabolic health

exercise testing for individuals with obesity

-Not often necessary prior to starting low-to moderate-intensity exercise program

- Higher risk for other conditions associated with CVD risk

- Timing of meds to treat comorbidities should be considered (Beta blockers, antidiabetic meds)

- Presence of musculoskeletal and orthopedic conditions may necessitate use of leg or arm ergometry

- Low exercise capacity may necessitate low initial workload & protocols to increase workload in small increments

aerobic frequency for obesity patients

≥ 5 d/wk

aerobic intensity for obesity patients

Moderate initially (≥40%-59% HRR); progress to vigorous (≥ 60% HRR or VO2R)

aerobic time for obesity patients

30 min/day(150 min/wk); increase to 60 min/day or more (250-300 min/wk)

aerobic type for obesity patients

prolonged, rhythmic activities, i.e. Swim, walk, water aerobics, water walking/jogging, biking, elliptical, rowing

resistance and flexibility frequency for obesity patients

2-3 d/wk

resistance intensity for obesity patients

60-70% 1RM; gradually increase to enhance strength and muscle mass

resistance time for obesity patients

2-4 sets of 8-12 reps for each major muscle group

resistance type for obesity patients

Similar to non-obese but modify based on fitness level, orthopedic concerns, and goals

flexibility intensity for obesity patients

Stretch to the point of mild discomfort or tightness

flexibility time for flexibility

Static stretch 10-30s; 2- 4 reps

flexibility type for flexibility

similar to non-obese

special considerations for obesity patients

- Set short- and long-term goals

- lose 3-10% of initial body weight over 3-6 months

- Reduce EI 500-1,000 kcal/day

- dont want to lose more than >1-2Ibs a week

- Create multiple intermediate goals to reach desired weight, esp. if > 10% reduction in BW

- More aggressive treatment may be needed

- Medically indicated very low-calorie diets

- Multidisciplinary team

- Behavior modification strategies

- Bariatric surgery