As researchers have searched for ways to slow the obesity epidemic worldwide, compelling evidence from adult populations has emerged suggesting that intake of specific types of foods and beverages – for example, sugary drinks, desserts, and refined grain products -- heighten the risk of excess weight gain over time. Although many experts agree that early childhood (ages 0 to 5 years old) is likely a critical period for the development of habits that influence obesity risk, particularly diet, there is very little high quality evidence on how dietary factors may influence excess weight gain among young children. We propose utilizing dietary data from 3-day food records and body mass index (BMI) data collected among the Children in Focus sub-sample of the Avon Longitudinal Study of Parents and Children in order to study how changes in dietary intake relate to changes in BMI during early childhood, from 18 months to 5 years old. This research can help us identify whether increasing intake of certain foods and beverages is linked with an increased risk of excess weight gain among young children, and can help inform policy strategies to prevent childhood obesity.