Background and Objectives: Diets with a specific omega-6/omega-3 fatty acid ratio have been reported to have favourable effects in controlling obesity in adults. However, development a local-based diet by considering the ratio of these fatty acids for improving the nutritional status of overweight and obese children is lacking. There- fore, using linear programming, we developed an affordable optimised diet focusing on the ratio of omega- 6/omega-3 fatty acid intake for obese children aged 12–23 months. Methods and Study Design: A cross- sectional study was conducted in two subdistricts of East Jakarta involving 42 normal-weight and 29 overweight and obese children, grouped on the basis of their body mass index for-age Z scores and selected through multi- stage random sampling. A 24-h recall was performed for 3-nonconsecutive days to assess the children’s dietary intake levels and food patterns. We conducted group and structured interviews as well as market surveys to iden- tify food availability, accessibility and affordability. Results: Three types of affordable optimised 7-day diet meal plans were developed on the basis of breastfeeding status. The optimised diet plan fulfilled energy and macronu- trient intake requirements within the acceptable macronutrient distribution range. The omega-6/omega-3 fatty ac- id ratio in the children was between 4 and 10. Moreover, the micronutrient intake level was within the range of the recommended daily allowance or estimated average recommendation and tolerable upper intake level. Con- clusions: The optimisation model used in this study provides a mathematical solution for economical diet meal plans that approximate the nutrient requirements for overweight and obese children.