A study of dietary intake in adult monozygotic twins.

As a part of a study of the dietary habits of monozygotic twins, a nutrition survey including a 24-hour dietary recall interview and a three-day dietary diary was conducted on the members of 15 male and 13 female pairs of identical Caucasian twins ranging from 25 to 61 years of age. In this study, overall mean caloric, protein, fat, and carbohydrate intake of males was significantly greater than females. Members of male twin pairs also tended to be more similar than female twins in mean intake of all major nutrient groups. In general, the observed differences in overall intake between males and females were maintained even after adjustment of body weight. Male twins were characterized by greater similarity in intake of sodium and potassium; however, there was no consistent difference in the degree of correlation in intakes of members of male and female twins for either iron, calcium or phosphorus.