Table 2.
Equations used to predict fat-free mass and lean soft tissue
| Author (year) | Number, sex (age)–BMI | Estimated component | Equation | Development | |
|---|---|---|---|---|---|
| R2 | SEE (kg) | ||||
| Equations used to estimate FFM | |||||
| Equations only using weight, age, sex, or BMI | |||||
| Gallagher et al.(2000)27* | 613, M (48 yr)–24.9 kg/m2† 1,013, F (44 yr)–24.9 kg/m2† | BF (%) | 76.0–1,097.8 × (1/BMI)–20.6 × sex (M:1/F:0)+0.053 × age (yr)+154 × sex (M:1/F:0) × (1/BMI)+0.034 × sex (M:1/F:0) × age (yr) | 0.9‡ | 4.31‡ |
| Janmahasatian et al. (2005)29 | 146, M (18–82 yr)–34.5 kg/m2 | FFM (kg) (M) | (9,270 ×weight [kg])/(6,680+216 × BMI) | 0.75 | RMSE: 3.52 |
| 157, F (19–79 yr)–34.7 kg/m2 | FFM (kg) (F) | (9,270 ×weight [kg])/(8,780+244 × BMI) | 0.76 | RMSE: 3.13 | |
| Larsson et al. (2006)24* | 274, M (31–61.8 yr)-26.2 kg/m2 | BF (kg) (M) | –30.84+1.120 ×weight (kg)/height (m) | 0.82 | 2.8 |
| 357, F (30.0–61.0 yr)–26.6 kg/m2 | BF (kg) (F) | –24.18+1.181 ×weight (kg)/height (m) | 0.88 | 2.1 | |
| Li et al. (2019)23 | 2,987, M (53.9 yr)–23.1 kg/m2 | FFM (kg) (M) | −25.498−0.051 × age (yr)+0.312 × height (cm)+0.263 ×weight (kg)+0.373 × BMI | 0.78 | 3.1 |
| 7,696, F (55.8 yr)–22.4 kg/m2 | FFM (kg) (M) For higher BMI | −74.474−0.025 × age (yr)+0.602 × height (cm)+1.077 × BMI | 0.74 | 3.3 | |
| FFM (kg) (F) | 8.032+0.534 ×weight (kg)+0.070 × height (cm)−0.533 × BMI | 0.70 | 2.4 | ||
| FFM (kg) (F) For higher BMI | 21.024+0.587 ×weight (kg)−0.019 × age (yr)−0.697 × BMI | 0.69 | 2.7 | ||
| Equations using the above parameters plus hip or WC | |||||
| Larsson et al. (2006)24* | 274, M (31–61.8 yr)–26.2 kg/m2 | BF (kg) (M) | 18.38–13.49 × height (m)+0.2572 ×weight (kg)+ 0.4567 × WC (cm) | 0.94 | 2.1 |
| 357, F (30.0–61.0 yr)–26.6 kg/m2 | BF (kg) (F) | 15.20–25.69 × height (m)+0.6276 ×weight (kg)+ 0.1069 × WC (cm) | 0.95 | 2.0 | |
| Equations used to estimate lean soft tissue | |||||
| Equations only using weight, age, sex, or BMI | |||||
| Lee et al. (2017)28§ | 5,239, M (42.7 yr)–26.6 kg/m2 | LST (kg) (M) | –14.729–0.071 × age (yr)+0.210 × height (cm)+ 0.468 ×weight (kg)–0.441 ×Mexican+0.320 ×Hispanic+ 1.821 × Black–0.784 × other ethnicity | 0.88 | 2.96 |
| 4,519, F (45.3 yr)–25.8 kg/m2 | LST (kg) (F) | –14.292–0.046 × age (yr)+0.201 × height (cm)+0.347 × weight (kg)–0.448 ×Mexican – 0.047 ×Hispanic+ 1.128 × Black–0.384 × other ethnicity | 0.85 | 2.39 | |
| Yu et al. (2013)31 | 188, Both (18–83 yr)–26.7 kg/m2 | LST (kg) | 22.93+0.68 ×weight (kg)–1.14 × BMI–0.01 × age (yr)+ 9.94 × sex (M:1/F:0) | 0.91 | 3.61 |
| Kulkarni et al. (2013)30 | 851, M (30.1 yr)–21.2 kg/m2 | LST (kg) (M) | –15.605–(0.032 × age [yr])+(0.192 × height [cm])+ (0.502 ×weight [kg]) | 0.90 | 1.92 |
| 481, F (34.7 yr)–23.2 kg/m2 | LST (kg) (F) | –13.034–(0.018 × age [yr])+(0.165 × height [cm])+ (0.409 ×weight [kg]) | 0.91 | 1.84 | |
| Equations using the above parameters plus hip or waist circumference | |||||
| Lee et al. (2017)28§,ǁ | 5,239, M (42.7 yr)–26.6 kg/m2 | LST (kg) (M) | 19.363+0.001 × age (yr)+0.064 × height (cm)+ 0.756 ×weight (kg)–0.366 × WC (cm)–0.066 ×Mexican+ 0.231 ×Hispanic+0.432 × Black–1.007 × other ethnicity | 0.91 | 2.55 |
| 4,519, F (45.3 yr)–25.8 kg/m2 | LST (kg) (F) | –10.683–0.039 × age (yr)+0.186 × height (cm)+ 0.383 ×weight (kg)–0.043 × WC (cm)–0.359 ×Mexican– 0.059 ×Hispanic+1.085 × Black–0.34 × other ethnicity | 0.85 | 2.38 | |
| Salamat et al. (2015)25 | 100, Both (47 yr)–28 kg/m2 | LST (kg) | 14.966+0.588 × BMI+18.694 × sex (M:1/F:0)+0.137 × HC (cm)–0.138 × age (yr) | 0.77 | 1.84 |
*For these equations, total body fat is calculated, and FFM is then estimated by subtracting fat mass from the total body mass; †Mean average age and BMI from three presented groups (three different ethnicities); ‡Gallagher et al.27 presented multiple R, and the SEE is presented for body fat %; §Authors call it lean body mass, but they explain that they subtracted bone from the lean value obtained from dual-energy X-ray absorptiometry and are therefore reporting lean soft tissue; ǁRace variables are binary (1 if yes, 0 if no), and white is the reference group.
BMI, body mass index; SEE, standard error of the estimate; FFM, fat-free mass; BF, body fat; RMSE, root mean square error; WC, waist circumference; LST, lean soft tissue; HC, hip circumference.