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13.2: Nutrition Calculations Reference Sheet

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  • Background Information: 1 kilogram = 2.2 pounds 1 inch = 2.54 centimeters 60 inches = 5 feet

    Anthropometric Calculations

    Hamwi Method for Ideal Body Weight (IBW)

    Female equation

    5 feet = 100#, every inch over add 5#

    Male equation

    5 feet = 106#, every inch over add 6#

    Ideal Body Weight Range (IBW range)

    Add/subtract 10% of IBW

    Percent Ideal Body Weight (% IBW)

    Actual Weight X 100


    Analysis of IBW

    Greater than 120% of IBW: Obese

    110%-120% of IBW: Overweight

    90%-109% of IBW: Adequate

    80%-89% of IBW: Underweight

    70%-79% of IBW: Moderately underweight

    Less than 70% of IBW: Severely underweight

    Percent Usual Body Weight (UBW)

    Actual Weight X 100


    Analysis of UBW

    Changes of 10% or less of no major concern unless person above or below IBW

    Changes of 10% or more need to be addressed, is weight gain or loss desired or planned

    Body Mass Index (BMI)

    Weight in pounds x 703

    (height in inches)2

    Analysis of BMI

    BMI< 18.5 = Underweight

    BMI 18.5 -24.9 = Normal

    BMI 25-29.9 = Overweight

    BMI 30 – 34.9 Class 1 Obesity

    BMI 35 – 39.9 = Class 2 Obesity

    BMI over 40 = Class 3 Extreme Obesity

    Waist Circumference

    Males < 40 inches = Healthy

    Females < 35 inches = Healthy

    Waist-to-Hip Ratio

    Waist Circumference / Hip Measurement

    Analysis of Waist-to-Hip Ratio

    Males > 0.9 Abdominal Obesity

    Females >0.85 Abdominal Obesity

    Body Fat Percentage


    2-4% body fat is essential 10-12% is essential

    6-13% is an athletic body fat range 14-20% is a healthy range for athletes

    14-17% is considered a 'fit' range 21-24% is healthy for fitness

    18-25% is acceptable 25-31% is an 'acceptable' range

    above 26% is considered obese above 32% is considered obese

    Fat Mass

    Body Weight x Body Fat %

    Lean Mass

    Body Weight – (Body weight x Body Fat %)

    Estimating Nutrients Needs for Adults

    Basal Metabolic Rate (BMR): Energy needed to keep you alive

    Male: weight in kg x 1 calorie/kg/hour x 24 hours

    Female: weight in kg x 0.9 calorie/kg/hour x 24 hours

    Total Energy Expenditure (TEE): Energy needed to keep you alive plus activity factor

    BMR x Activity Factor

    Sample Activity Factors:

    Confined to bed: 1.2

    Out of bed, low activity 1.25

    Average activity 1.65

    Highly active 2.0

    Quick Determination of Total Energy Expenditure (TEE)

    • Another method for estimating daily energy needs for adults

    • Used frequently in a clinical setting

    Weight in kilograms x Activity factor

    Activity/stress Factor:

    Minimal Activity (bedridden): 25 kcal x kg

    Normal Activity (ambulatory): 30 kcal x kg

    Moderate Activity (exercise 3x/week): 35 kcal x kg

    Increased Activity (exercise 5x/week): 40 kcal x kg

    Intense Activity (exercise daily): 45 kcal x kg

    Determining Protein Needs

    Weight in kg X protein factor

    Protein Factor:

    Normal activity 0.8gm/kg/day

    Daily physical activity 1.0-1.2 gm/kg/day

    Heavy daily physical activity 1.2-1.5 gm/kg./day

    Determining Fluid Needs

    • Can determine based on calorie intake OR weight

    1 ml of fluid for every calorie intake


    Weight in kg x Fluid factor

    Fluid Factors:

    25 ml X kg body wt for > 75 yo or inactive

    30 ml X kg body wt for 55-75 yo or moderately active

    35 ml X kg body wt for 20-55 yo or moderately active

    40 ml X kg body wt for 16-30 yo or highly active

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