The number of overweight children is increasing worldwide. Known risk factors are overweight parents and a diet rich in sugar and fat. Other suspected risk factors for future obesity are

• gaining a lot of weight quickly in the first months of life 
• a “difficult” temperament, i.e. excessive crying, hard to comfort and put to bed. Limited research in USA suggests that such babies are fed more to pacify them.

Normal weight

Researchers at the Institute investigated whether Norwegian infants with difficult temperaments weighed more and gained weight faster than other infants. The results contradict findings from other studies.

- We saw that infants with difficult temperaments were not overweight. On the contrary, the birth weights of the most difficult children were below average, explains researcher Susan Niegel from the Division for Mental Health.

By six months old, the babies with difficult temperaments had a normal weight.

- These infants were no quicker to gain weight than other infants. Any difference in weight gain was insignificant, adds Niegel. Due to the large size of the cohort in the Mother and Child Study these findings are important.

Further research

The study cannot rule out that children with difficult temperaments may gain weight later. The hypothesis that these children are fed more is not weakened by these findings. An ongoing study at the Institute is investigating whether infants with difficult temperaments eat differently from their peer group.

This study was financed by the Norwegian Foundation for Health and Rehabilitation. It was completed as part of the Mother and Child Cohort Study where data was collected from 29 000 women in the form of questionnaires.