Appropriate infant and child feeding practices and balanced nutrition can significantly reduce malnutrition and can contribute to optimal physical, mental, and developmental growth of children. Childhood obesity is a major public health concern in the United States and is associated with both physical and psychological consequences and decreased health-related quality of life. Early life feeding practices and nutrients intake starting from birth to 2 years can significantly contribute to the development of obesity. This dissertation aimed to develop three manuscripts to understand the association between infant feeding practices including bottle feeding practices, initiation of added sugar and added sugar intake, and children’s BMI-for-age percentile at 36 months old among Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) participants. First manuscript examined the association between added sugar consumption at young age and BMI-for-age percentile at 36 months old among WIC participants. Second manuscript examined factors associated with initiation of added sugar among WIC participants. Third manuscript examined the association between usual daily intake of added sugar at young age and BMI-for-age percentile at 36 months old among WIC participants. Data were from the WIC Infant and Toddler Feeding Practices Study-2 (ITFPS-2). The ITFPS-2, a longitudinal study of WIC participants (mothers and their children) began in 2013. First, Cox proportional hazards model was used to identify factors associated with bottle cessation, and multivariate linear regression to examine the association between age of bottle cessation and BMI. Second, Cox proportional hazards model examined factors associated with introducing added sugar. Third, bivariate analysis was used to examine the association between usual daily intake of added sugar before age 2 years old and BMI-for-age-percentile at 36 months old. The first research study indicates about 34% of children used a bottle longer than 12 months, and 13% longer than 18 months. Bottle cessation at older ages was associated with Hispanic ethnicity, multiparity, low income, low education, higher caregiver weight, and not initiating breastfeeding, and adjusted children’s BMI-for-age percentile at age 36 months increased by 0.47 for each additional month of bottle use. The second research study indicates about 25% of children initiated added sugar at or before 7 months. Contributing factors were caregiver’s race/ethnicity, education, employment, weight status, parity, child sex, and premature birth (all p<0.05). The third research study indicates the mean added sugar intake ≤7 months, 8-13 months, and 14-24 months were 0.23 teaspoon (tsp), 3.44 tsp, and 11 tsp, respectively. Bivariate analysis indicates added sugar intake before 2 years old is associated with children’s BMI-for-age-percentile at 36 months old. These research studies indicate a need for health care advocacy programs and intervention to educate the caregivers to practice appropriate feeding practices among infants and children aged 2 or younger.