Objective: To assess the effectiveness of an eight-week nutrition and physical activity intervention, entitled: “My Healthy Habits”, at summer camps to prevent obesity, reduce screen time, promote healthy eating habits and physical activity among children. Material and Methods: Eight-week pretest-posttest: intervention versus a comparison group was conducted, in two comparable summer camps in Kuwait and randomized at the site level. Convenient sampling (n=79) included children aged 6-10, receiving 8 weeks of nutrition education: 2 days/week, 40 minutes/day and physical activity sessions: 4 days/week for 20 minutes/day. Outcomes included: the Modified Healthy Habits Survey (items about diet, physical activity and sedentary behavior) and anthropomorphic: Body mass index (BMI) for age and gender percentile and waist-to-height ratio (WHtR). Group changes were measured by independent t-test, and within group changes by the McNemar’s test (categorical data) and paired t-test (interval data). Results: Significant increases in nutrition knowledge scores (from 4.3±1.7 to 10.5±1.2) and in the total score of the major food groups (from 10.0±2.6 to 13.7±2.2) were observed from pretest to posttest. Healthy eating significantly increased (from 12.8±1.8 to 14.5±1.5) for the intervention group only; however, intake of French fries, chips (FF) and sugarsweetened beverages (SSB) remained the same for both groups. Physical activity increased and screen time decreased,only in the intervention group. The participants’ BMI and WHtR decreased significantly in the intervention group: p-value=0.001. Conclusion: Healthy food and physical activity increased, while screen time decreased. Consumption of unhealthy food (FF and SSB) remains an issue.