Adolescent immigrants and refugees are at elevated risk for obesity, however, gaps remain regarding specific diet and lifestyle changes. This study examined: (1) weight status, behaviors and perceptions, (2) diet patterns and changes, (3) sociodemographic and dietary factors associated with BMI. Cross sectional survey, anthropometric measures were conducted at a school for newcomer youth in North Carolina. Data analysis included descriptive, frequency, bivariate and linear regression. Participants (n = 68, 55% female, < 1 year US) included immigrants and refugees ages 12-17. Thirty-one percent were overweight or obese. Forty-seven percent had attempted to lose weight. Positive weight perceptions were associated with normal BMI (p = 0.010). Fruit, milk, fruit juice, soda, and meat consumption increased post-arrival (p = 0.037, p = 0.010, p = 0.003, p = 0.044, p = 0.014, respectively). Dietary change was positively associated with BMI (p = 0.002). Adverse diet and lifestyle changes occur rapidly, are associated with obesity, and weight control behaviors and concerns warrant early intervention.