Fatty acids are said to be saturated, monounsaturated, or polyunsaturated. Saturated fats are mainly of animal origin and unsaturated fats are found mostly in plant products. Example of foods high in saturated fatty acids are meats, meat fat, lard, whole milk, cream, butter, cheese, ice cream, hydrogenated oils, coconut oil, and palm oils. Limited data suggests that eating one or two servings of fish weekly lessens the risk for coronary heart disease. Because lipids do not dissolve in water, lipoproteins transport fat in the blood.
Lipoproteins are a combination of lipids covered by proteins.
Proteins are the main substances the body uses to build and repair tissues such as muscles, blood, internal organs, skin, hair, nails, and bones. Proteins can be used as a source of energy. Proteins are used for energy if carbohydrates are not available. Excess proteins may be converted to glucose or fat to be used for energy or stored as fat. The main sources of protein are meats, tuna, beans, milk, and other dairy products.