get_weight_class {httk}

Assign weight class (underweight, normal, overweight, obese)

Description

Given vectors of age, BMI, recumbent length, weight, and gender, categorizes weight classes using CDC and WHO categories.

Usage

get_weight_class(age_years, age_months, bmi, recumlen, weight, gender)

Arguments

age_years

A vector of ages in years.

age_months

A vector of ages in months.

bmi

A vector of BMIs.

recumlen

A vector of heights or recumbent lengths in cm.

weight

A vector of body weights in kg.

gender

A vector of genders (as 'Male' or 'Female').

Details

According to the CDC (https://www.cdc.gov/obesity/basics/adult-defining.html), adult weight classes are defined using BMI as follows:

Underweight

BMI less than 18.5

Normal

BMI between 18.5 and 25

Overweight

BMI between 25 and 30

Obese

BMI greater than 30

For children ages 2 years and older, weight classes are defined using percentiles of sex-specific BMI for age, as follows (Barlow et al., 2007):

Underweight

Below 5th percentile BMI for age

Normal

5th-85th percentile BMI for age

Overweight

85th-95th percentile BMI for age

Obese

Above 95th percentile BMI for age

For children birth to age 2, weight classes are defined using percentiles of sex-specific weight-for-length (Grummer-Strawn et al., 2009). Weight above the 97.7th percentile, or below the 2.3rd percentile, of weight-for-length is considered potentially indicative of adverse health conditions. Here, weight below the 2.3rd percentile is categorized as "Underweight" and weight above the 97.7th percentile is categorized as "Obese."

Value

A character vector of weight classes. Each element will be one of 'Underweight', 'Normal', 'Overweight', or 'Obese'.

Author(s)

Caroline Ring

References

Ring CL, Pearce RG, Setzer RW, Wetmore BA, Wambaugh JF (2017). “Identifying populations sensitive to environmental chemicals by simulating toxicokinetic variability.” Environment International, 106, 105–118.

Barlow SE. Expert committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report. Pediatrics. 2007;120 Suppl 4. doi:10.1542/peds.2007-2329C

Grummer-Strawn LM, Reinold C, Krebs NF. Use of World Health Organization and CDC growth charts for children Aged 0-59 months in the United States. Morb Mortal Wkly Rep. 2009;59(RR-9). https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5909a1.htm