Fats separate the starch granules in flour. The more thoroughly fat mixes with the starch, the smoother the baked product. Carbohydrates contribute 4 calories per gram, proteins 4 calories per gram, and fats 9 calories per gram. All fats, including margarine and butter, fit at the top of the food guide pyramid, in the little triangle that includes foods we should eat sparingly. This is because fats provide energy but few other nutrients.
Some adverse effects occur from eating too much fat, including butter or margarine.
Elevated levels of serum cholesterol have been identified as a risk factor in heart disease. Evidence suggests that people can help lower cholesterol levels by controlling the amounts of fat and cholesterol they eat. This is why the dietary guidelines recommend that people older than age 2 limit fat consumption to no more than 30 percent of total calories. High fat consumption also is associated with increased risk of hypertension and some forms of cancer. Some controlled studies have shown that reducing fat consumption might lower blood pressure.