Fat is the body’s major energy storage system. When the energy from the food you eat and drink can’t be used by your body, the body may turn it into fat for later use. Your body uses fat from foods for energy, to cushion organs and bones, and to make hormones and regulate blood pressure. Some fat is also necessary to maintain healthy skin, hair and nails, so you shouldn’t cut all fat out of your diet. But in general, most people in the United States consume too much fat – which can lead to heart disease, obesity, diabetes and many other health problems.
Types of Fats
Not all fats are created equal. Saturated fats, which are generally solid at room temperature, are the least healthy and tend to increase the level of cholesterol in your blood. Foods that contain saturated fat include butter, cheese, some margarines, shortening, tropical oils such as coconut and palm oil and the fats in meat and poultry skin, so you should try to limit your consumption of those oils and foods.
Unsaturated fats reduce blood cholesterol when they replace saturated fats in the diet. There are two types of unsaturated fat - monounsaturated fat and polyunsaturated fat. Monounsaturated fats have been shown to raise the level of HDL, the ‘good’ cholesterol that protects against heart attacks, in the blood, so in moderation they can be part of a healthy diet. Olive and canola oils, peanut butter and nuts are particularly high in monounsaturated fats. The American Heart Association (AHA) recommends that you limit calories from monounsaturated fat to no more than 15% of your total calorie intake.
Although polyunsaturated fats come from plants and fish, but they may be more likely to form free radicals and lead to tissue damage. Good sources of polyunsaturated fats include most other vegetable oils and high-fat fish such as salmon and tuna. The AHA also recommends that saturated and polyunsaturated fats should make up less than 10 percent of your calorie intake.
Partially hydrogenated vegetable oils, such as those used in many margarines and shortenings, contain unsaturated fats called trans-fatty acids. Trans-fatty acids may raise blood cholesterol levels, although not as much as saturated fat.Adjusting Fat Intake for Weight Loss or Gain
If you want to lose body fat, limit your intake of high-fat foods. This will not only improve your metabolism, it will allow you more food for your calorie expenditure because fats have more than twice the calories per gram as proteins (which contain 4 calories per gram) and carbohydrates (also 4 calories per gram).
But just because a food is low in fat doesn’t mean you can eat all you want and not gain weight. Low-fat and no-fat foods still contain calories, so it’s possible to gain weight from eating too many low-fat foods. Keep your serving sizes and calories under control while monitoring your fat intake, and you’ll be better able to manage your weight. It’s also a good idea to choose foods for their nutrient content - not just fat-free or low-fat versions of low-nutrient foods such as cookies, cakes and candy. Fruits, vegetables and whole grains contain plenty of vitamins and minerals, while being naturally low in fat.
To use up your body’s fat storage, you need to exercise regularly. Moderate aerobic exercise, which raises your heart rate, is especially important. And any exercise that builds muscle mass can also help you burn more calories because muscle burns more calories than fat.
If you’re trying to gain weight, you may want to add more high-calorie, high-fat foods. But try to limit the saturated fats in your diet. Exercise is also important because it will help to ensure that the weight you gain is more muscle and less fat.