Drosophila is an emerging model organism in which to study the effects of diet on the regulation of metabolism and physiological function. In order to analyze the effects that different diets and food additives have on the accumulation of lipids in Drosophila larvae, we have established a control diet and optimized an established method to monitor the accumulation of lipids in third instar Drosophila larvae known as the floating larvae assay. We report on the simplicity and utility of using the floating larvae assay to access changes in lipid accumulation in flies raised on different diets.