But not all fats are the same. You should try to avoid

Try to replace them with oils such as canola, olive, safflower, sesame, or sunflower. Of course, eating too much fat will put on the pounds. Fat has twice as many calories as proteins or carbohydrates.

Monounsaturated fats have been shown to improve blood cholesterol levels. 


Polyunsaturated fats：

Polyunsaturated fats can lower bad cholesterol levels (LDL cholesterol). One type is omega-3, which can help prevent clotting of blood, reducing the risk of stroke and also helps lower triglycerides, a type of blood fat linked to heart disease. 

More important than total fat intake is what kind of fats you eat and from which foods. Unsaturated fats, for example, are healthier choices than foods rich in saturated fat from animal sources, foods containing partially hydrogenated oils and trans fat, and foods high in refined carbohydrates, starches, and sugars.

Unsaturated fats exist in two forms: polyunsaturated and monounsaturated. You can obtain polyunsaturated fats from salmon and other fatty fish as well as corn, soybean, safflower, and cottonseed oils. Rich sources of monounsaturated fats include olives and olive oil, canola and peanut oils, and most nuts.

The most unhealthy type of fat is trans fat from partially hydrogenated oils. Trans fats form when vegetable oils are processed to make them more solid at room temperature. You'll find trans fats in many baked goods (such as donuts, muffins, and pie crusts), snack foods (crackers, popcorn),
and some fried foods. No amount of trans fat from partially hydrogenated oils is considered healthy.

When eaten in large amounts, all fats, including healthy fats, can contribute to weight gain. Fat is higher in energy (kilojoules) than any other nutrient and so eating less fat overall is likely to help with weight loss.

Eating less saturated and trans fats may help lower your risk of heart disease. When buying products check the labels and choose the varieties that are lower in saturated and trans fats and higher in poly and monounsaturated fats.

So a diet that is low in saturated fats and trans fats, but that also includes moderate amounts of unsaturated fats will help you stay healthy.

2. Eat more fish and chicken. Substitute ground turkey or chicken for ground beef. Remove the skin from chicken before cooking.

3. Eat leaner cuts of beef and pork, and trim as much visible fat as possible before cooking.

4. Bake, broil, or grill meats; avoid frying. Avoid breaded meats and vegetables.

5. Use fat-free or reduced-fat milk instead of whole milk. Instead of sour cream, try nonfat plain yogurt or a blend of yogurt and low-fat cottage cheese. Use low-fat cheeses.

6. In recipes, use two egg whites instead of one whole egg.

7. Avoid cream and cheese sauces, or make recipes with low-fat milk and cheese.

8. Instead of chips, snack on pretzels or unbuttered popcorn.

9. Limit hydrogenated fats (shortening, lard) and animal fats (butter, cream) if you can. Use liquid oils, particularly canola, olive, safflower, or sunflower.

10. Read the nutrition labels on all products. Many “fat-free” products are very high in carbohydrates, which can raise your triglyceride levels.

11. Compare the fat content of similar products. Do not be misled by terms like “light” and “lite.”

12. When eating in a restaurant, ask that the sauces and dressings be served on the side.

13. Look for hidden fat. For example, refried beans may contain lard, or breakfast cereals may have significant amounts of fat.

14. Try cooking with herbs, spices, lemon juice, etc., instead of butter or margarine.