Table 2. Heritability estimates obtained in 149 nuclear families as part of the Kiel Obesity Prevention Study ⁶⁹ .

	Three generations	Two generations (old)	Two generations (young)
FFM (kg)	0.304	0.729	0.430
FM (kg)	0.504	0.562	0.542
REE (kcal/24h)	0.442	0.535	0.447
REEFFM (kcal/24h)	0.419	0.453	0.455
Residuals of REE on FFM	0.347	0.387	0.384

Abbreviations: FM, fat mass; FFM, fat-free mass; REE, resting energy expenditure; REE_FFM, fat-free mass adjusted resting energy expenditure.

The study population is characterized in Table 1. We have used variance component methods as implemented in SOLAR with extended pedigrees to obtain heritability estimates (see Blangero et al.⁷⁷). Calculations were based on either three generations (grandparents, parents and children) or two generations (old: pairs of grandparents and parents; young, pairs of parents and children).