To examine sex differences and longitudinal changes in ready-to-eat (RTE) cereal and breakfast consumption in the Dietary Intervention Study in Children, and the relationship between RTE cereal intake with nutrient intake, blood lipids, and body mass index (BMI).

Secondary analyses based on data from Dietary Intervention Study in Children, a randomized, controlled, multicenter, clinical trial with five sets of three 24-hour recalls.

Children (n=660) from six clinics aged 8 to 10 years at study entry. Participants had serum low-density lipoprotein cholesterol levels between the 80th and 98th percentiles for age, and were followed for a mean of 7.5 years.

Children were randomized to a total fat- and saturated fat-modified dietary intervention or usual care.

Frequency of RTE cereal and breakfast consumption was examined by sex and age. Mixed models by sex were used to examine the relationship of RTE cereal consumption to average daily intake of nutrients, blood lipids, and BMI.

For all children, RTE cereal and breakfast consumption declined with age. Boys consumed RTE cereal more often compared with girls. Except for energy, RTE cereal consumption was positively associated with all measures of nutrients for both sexes. In boys, higher RTE cereal consumption was associated with lower total and low-density lipoprotein cholesterol levels and lower BMI.

Food and nutrition professionals should continue to educate youth and their parents on the nutritional benefits of routinely eating RTE cereal.