Trout fed full-fat soybean diets were significantly fatter. Channel catfish fed protein but much more fat than fish fed diets containing solvent extracted soybean meal. Full-fat soybean meal contains 18% fat compared with 0.5% fat for solvent-extracted soybean meal. The improves the nutritional quality of the diet. Too much fat can cause an imbalance of protein and energy in the ration, which can reduce nutrient intake and also produce fatty fish. The additional fat in full-fat soybean meal would be more beneficial to coldwater fish, who do not utilize carbohydrates well for energy.