Components of Food
If you are trying to make heart-healthy changes to your lifestyle and diet, it is helpful to know some basics about nutrition, starting with the components of food.
- You need enough calories to maintain your energy level, but no more than you can burn off. This is called an energy balance.
- If you take in more calories than you burn, you gain weight.
- If you take in fewer calories than you burn, you lose weight.
- If you balance the two, you maintain your weight.
- Even when you are dieting, however, calories should not be cut back so much that your energy needs are not met. The number of calories you need depends primarily on age, gender, and activity level.
- Remember: "cholesterol-free" does not mean "fat-free."
- Dietary cholesterol is a fat-like substance found in all foods of animal origin: egg yolks, meat, poultry, fish, milk, and milk products.
- Because our bodies make cholesterol, it is not required in our diets. However, because most people eat foods that contain cholesterol, it is important to avoid excessive amounts. The amount of cholesterol you consume can affect your blood cholesterol levels.
Fatty acids are the basic chemical units in fat. They may be saturated, polyunsaturated, monounsaturated, or trans fats. These fatty acids differ in their chemical compositions and structures, and in the way in which they affect your blood cholesterol levels, according to the following:
- Saturated fat:
- Is used by the liver to manufacture cholesterol.
- Has been shown to raise blood cholesterol levels, particularly the LDL or "bad" cholesterol level which can increase your risk of heart attack and stroke.
- Should comprise no more than 10 percent of your daily calorie intake.
- Saturated fat can be found in: meats, butter, cocoa butter, coconut, and palm oils.
- Polyunsaturated fats:
- Do not appear to raise blood cholesterol levels.
- Examples include: safflower, sunflower, corn, and vegetable oils, and soybean oils.
- Monounsaturated fats:
- Do not seem to increase bad cholesterol levels and may help boost HDL or "good" cholesterol in the blood. Increased HDL levels have been linked to a lower risk of heart disease.
- Examples include olive and canola oils.
- Trans fats: by-products of hydrogenation, a chemical process used to change liquid unsaturated fat to a more solid fat. Structurally similar to saturated fat, trans fatty acids may have a great impact on raising total and LDL cholesterol levels. Trans fats should be avoided as much as possible.
- Examples include stick margarine and fats found in commercially prepared cakes, cookies, and snack foods.
Total fat intake should be no more than 30 percent of your daily calorie intake.
- All fats contain about the same number of calories teaspoon for teaspoon. There is no low-fat fat.
- Fat is the most concentrated source of calories, supplying more than twice as many calories per gram as either carbohydrates or proteins.
- Most people tend to get far too much fat in their diet, which contributes to health problems, such as obesity, high blood cholesterol, and heart disease. While coconut and palm oils contain no cholesterol, they are high in saturated fat and should be avoided.
- Fiber is the indigestible portion of food.
- There are two types of fiber: soluble and insoluble.
- Soluble fiber. Fiber found in foods such as oat bran and dried beans that can lower blood cholesterol in some people.
- Insoluble fiber. Fiber found in foods such as wheat bran and is known to have many health benefits. While this type of fiber has not been found to lower cholesterol, it is useful in weight control because it creates a feeling of fullness.
- Although salt is the major contributor of sodium in our diets, sodium and salt are not the same, contrary to popular belief. A teaspoon of table salt contains 2,300 milligrams of sodium.
- Sodium is a mineral needed to maintain body fluids and proper nerve function. It occurs naturally in some foods, but most of the sodium in our diets comes from seasonings and ingredients we add to foods.
- Although sodium is essential, most of us consume more than we need. In some people, too much sodium in the diet can cause the blood pressure to rise, putting them at risk for heart disease and stroke.
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