DIET AND BEHAVIORAL ACTIVITY IN 12-WEEK-OLD INFANTS

Deposition of excess dietary energy occurs if energy intake exceeds ex penditure. Anthropometric differences between breast-fed and formula-f ed infants due to differences in energy deposition are frequently repo rted. It has been suggested that infant obesity may result from decrea sed levels of energy expenditure on physical activity. Infant diet may therefore influence energy balance by affecting behaviour and hence e nergy expenditure. Behavioural and motor activity of 25 formula-fed an d 25 breast-fed infants were compared using activity diaries, temperam ent questionnaires and actometers. There were no anthropometric differ ences between the two groups. The breast-fed infants fed significantly more slowly than the formula-fed infants despite taking in similar mi lk volumes, and also fed significantly more frequently. Otherwise ther e were no significant differences between the two groups with respect to the daily time spent awake and content, asleep, fussy, or crying, n or with respect to gross motor activity and temperament. It is unlikel y that energy balance of the two groups differed significantly on acco unt of behavioural activity.