The study is designed to assess habituation of behavioral responding for food as risk factors for increases in Standardized Body Mass Index (zBMI) over two years in non-overweight children.

Cross sectional data have shown slower habituation is related to greater energy intake, and habituation is slower for overweight/obese compared to leaner youth, but it is not known whether this is a result of being overweight, or whether slower habituation is a risk factor for weight gain. The goal of this application is to study individual differences in behavioral (responding for food) habituation as risk factors for alterations in zBMI and body fat over a two year period in 200, 8 to 12 year-old non-overweight children. This project will provide the first test of the hypothesis that slow habituation to food is a risk factor for increases in zBMI in non-overweight youth.

Inclusion Criteria:

• 8-12 years of age
• Participants will include children who are at the 50th BMI percentile and less than the 85th BMI percentile (BMI = kg/m2) at baseline. We will also include children who are below the 50th percentile, but have at least one biological parent with a current BMI ≥ 25 kg/m2.

Exclusion Criteria:

• Food allergies or special diets: Youth should have no dietary restrictions that could interfere with these experiments, including food allergies or religious or ethnic practices that limit food choice or medical conditions which alter nutritional status or intestinal absorption (e.g. inflammatory bowel disease).
• Activity restrictions: Children who have activity restrictions due to medical or physical problems, such as uncontrolled exercise induced asthma or a disability requiring wheelchair use will not participate.
• Psychopathology, medications or sickness: Children should have no psychopathology (e.g. childhood schizophrenia) or developmental disabilities that would limit participation. Children will also be excluded if they are taking medications that could affect their level of activity or appetite (e.g. methylphenidate).
• Moderate or greater liking of study foods. Children must report at least a moderate liking ( 3 or greater on a 5-point Likert-type scale) of the foods used in these studies and be willing to consume them.

2 years

Only participation-related adverse events were collected.