Determining and Controlling Body Composition

Vocabulary

  • body mass index (BMI): A ratio that allows you to assess your body size in relation to your height and weight.

  • energy balance: The number of calories an individual consumes in comparison to the amount of calories they burn.

Determining Body Composition

  • Measuring body composition is more difficult than weight

  • Most accurate methods require professional help

Measure methods include:

  • Body mass index

  • Skin fold measurement

  • Waist circumference & Waist-to-Hip ratio

  • Bioelectrical impedance

  • Hydrostatic Weighing

  • Magnetic Resonance Imaging

Body Mass Index

  • Uses statistical data of weight and height across the population

  • Does not measure body fat directly

  • Relies on a correlation between weight and body fat

  • Does not account for body frame size or muscles content

Calculating BMI

Step 1: Multiply height in inches by .0254

Step 2: Multiply height result by itself

Step 3: Divide body weight in pounds by 2.2

Step 4: Divide weight result by height result

Step 5: BMI Results

BMI Ranges

Underweight

<18.5

Normal

18.5-24.9

Overweight

25.0-29.9

Obesity

30.0-39.9

Extreme Obesity

>40.0

Skin Fold Measurement

  • Measure of skin fat thickness at several points on the body

  • Skin is gathered and thickness measured with calipers

  • Results are combined and compared to statistical data

  • Determining body fat from measurements can be difficult

  • Accuracy is questionable and is based upon test administrator

Waist Circumference

  • Measurement around the waist

  • Quick indicator of abdominal fat

  • Many health risks associated with high abdominal fat

Disease Risk

Males

>40 inches

Females

>35 inches

Waist-to-Hip Ratio (WHR)

Measure

  • Waist circumference (WC)

  • Hip circumference (HC)

Find ratio using the equation:

WHR = WC / HC

Disease risk

Males

>.94

Femlaes

>.82


Bioelectrical Impedance

  • Low level electrical signal is passed through the body

  • Electrical signal flows more easily through lean body mass

  • Signal speed combined with the following factors determine body fat percentage

Hydrostatic Weighing

Comparison of normal weight to underwater weight

  • Density of body is then used to determine body fat percentage

  • Entire body must be submerged below water

  • Once below water, weight is measure and compared to normal weight

  • More accurate method for measuring body fat

Keys to Controlling Body Composition

Energy Balance

  • Result of energy intake versus energy used

FITT Principle

  • Frequency

  • Intensity

  • Time

  • Type

Energy Balance

  • Energy balance is a major factor in body composition

  • Everyone has complete control over this factor

  • Energy intake should be equal to energy used

  • Caloric intake controlled by energy/foods taken in

  • Energy used can be manipulated through exercise

  • Intake = Used

  • Maintain weight

  • Intake > Used

  • Weight Gain

  • Intake < Used

  • Weight loss

Frequency

  • Can be applied to food intake and exercise

  • Eat smaller meals more often

  • Four to six meals per day is recommended

  • Do not skip meals

  • Combine with exercise 3-5 times per week

  • Should include cardiovascular and resistance training

Intensity

  • Can be applied to food intake and exercise

  • Adjustment of the number of calories consumed

  • Average adult daily intake = 2000 calories

  • Eat less than average caloric intake to lose weight

  • More exercise increases energy used

  • Use Max Heart Rate to set intensity level

  • Max heart rate = 220-Age


Time

  • Plan to lose weight/fat slowly

  • 2 pounds per week is considered a safe weight loss amount by medical professionals

  • Effective Exercise

  • Beginners start at 15-60 minutes per session

  • Progress to longer sessions as body adjusts

Type

  • Cardiorespiratory or Resistance Training

  • Cardiorespiratory training includes running, cycling, and swimming

  • Resistance training includes weight, lifting, resistance bands, and body weight exercises

Strategies for Achievement

  • Meal Control

  • Journal Experiences

  • Busting Weight Loss Myths

  • Proper Hydration

  • Goals and Rewards

Meal Control

  • Eat more frequent, smaller meals

  • Skipping a meal puts body into starvation mode

  • Metabolism slows down to compensate

  • Usually end up eating a much larger next meal

Journal Experiences

  • Track daily diet and exercise

Busting Weight Loss Myths

  • Fad diets often promise quick weight loss and don’t deliver

  • Weight is gained over time and must be lost over time

  • To lose, you must eat less energy than you use on a daily basis

  • Can increase energy use by exercising 3-5 times a week

Proper Hydration

  • Drink proper levels of water throughout the day

Goals and Rewards

  • Set goals for your plan

  • When you reach a goal pick a personal reward

  • Make the reward something you wouldn’t normally do

  • Be sure to avoid over-eating as a reward