This is a cohort study where families with infants are followed closely for three years. It aims to assess if parental weight status (normal weight vs. overweight/obesity), their physical activity and eating habit will influence their young children's growth and be helpful in childhood obesity reducing.

The aimed 300 families are invited with half parents in high risk group (one of the parents with BMI>=28 or both 28>BMI>=24) and half in low risk group (both parents with BMI<24 or one parent 28>BMI>=24) living in Wuhan City. Maternal and paternal prepregnancy weight and height are recruited through the Children Systematic Health Management System before the child's first birthday. After getting an oral agreement, a later on family visit will be done by trained staffs. The home visit contains anthropometrics measurement, including weight, height, head circumference, abdominal circumference for both parents and children and blood pressure for parents; it also has some questionnaires that have children's condition during the first years, the caring status, parents' characteristic information, the eating, physical activity and sleeping habits for both parents and children, children's seven day 24 hours' sleeping record in the coming week; at the same time, objectively measured physical activity for parents and children will be done for seven days with accelerometers. The annual visit will range 15 days before or after the children's birthday, and this will begin from the children age one and followed up to aged three.

Inclusion Criteria:

• a child in the household being 1 year old (±3 months) at the time of recruitment;
• the parents were Wuhan registered residents;
• the child had no chronic health condition affecting growth, physical activity or eating habits.

Exclusion Criteria:

• none.

Families living in Wuhan city, having an one year old child, willing to participanted are welcomed to the study. A total of 300 simple size with half high-risk group and half in low-risk group is anticipated.