An anthropometry-based equation of fat mass percentage as a valid discriminator of obesity

Public Health Nutr. 2019 May;22(7):1250-1258. doi: 10.1017/S1368980018004044. Epub 2019 Feb 15.

Abstract

Objective: To develop a new predictive equation for fat mass percentage (%FM) based on anthropometric measurements and to assess its ability to discriminate between obese and non-obese individuals.

Design: Cross-sectional study.

Setting: Mexican adults.ParticipantsAdults (n 275; 181 women) aged 20-63 years with BMI between 17·4 and 42·4 kg/m2.

Results: Thirty-seven per cent of our sample was obese using %FM measured by air-displacement plethysmography (BOD POD®; Life Measurement Instruments). The fat mass was computed from the difference between weight and fat-free mass (FFM). FFM was estimated using an equation obtained previously in the study from weight, height and sex of the individuals. The %FM estimated from the obtained FFM showed a sensitivity of 90·3 (95 % CI 86·8, 93·8) % and a specificity of 58·0 (95 % CI 52·1, 63·8) % in the diagnosis of obesity. Ninety-three per cent of participants with obesity and 65 % of participants without obesity were correctly classified.

Conclusions: The anthropometry-based equation obtained in the present study could be used as a screening tool in clinical and epidemiological studies not only to estimate the %FM, but also to discriminate the obese condition in populations with similar characteristics to the participant sample.

Keywords: BMI; Body composition; Discriminant analysis; Fat mass; Obesity; Prediction equations.

MeSH terms

  • Adipose Tissue / metabolism*
  • Adult
  • Anthropometry / methods*
  • Body Mass Index
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Mexico
  • Middle Aged
  • Obesity / metabolism*
  • Plethysmography
  • Sensitivity and Specificity