Margarine is loaded with partially or fully hydrogenated fats, which raise your bad LDL cholesterol, increasing your risk for heart disease, inflammation and stroke. Butter has fewer processed ingredients and is better for you than margarine, but the saturated fat it packs can contribute to weight gain. If you like avocados, use them as a butter substitute, spreading mashed avocado or prepared guacamole on toast or crackers. If you must have butter, whipped butter is better because more air means less fat and fewer calories.