ABSTRACT
Obesity frequently aggregates in families. The first large family study known to the authors was published in 1923 by Davenport, who investigated more than 500 families with 3582 parent-offspring pairs (1). Familial resemblance in obesity phenotypes is caused not only by genetic factors, but also by shared environmental factors, possibly related to lifestyle and culture. Body mass index (BMI) is by far the most frequently studied measure of fatness in family studies and the present chapter focuses on this phenotype. However, other measures related to fatness such as skinfold thickness and waist circumference, are also briefly mentioned (see Chapter 1.1).
