What do fats do in my diet?

Fats actually have a job to do. You cannot live without them. In our bodies, fats do the following:

  • Some vitamins only work in the body when taken with fat (like vitamins A, D, E and K).
  • Fat is important for proper growth and proper functioning and health of our skin, brain and nervous system.
  • Fat adds flavor to food.
  • Fat can help you feel full after a meal or snack.

What are the different types of fats?

There are many types of fats. Some are healthy and some are unhealthy.

Healthy fats
Healthy fats are called unsaturated fats. Unsaturated fats are better choices than saturated fats. Unsaturated fats are liquid at room temperature. They come mostly from plants.

There are two types of unsaturated fats, which include:

  • Monounsaturated fats. Examples include olive oil, canola oil avocado and nuts.
  • Polyunsaturated fats. Examples include oils from safflower, sunflower, corn, soybeans, fatty fish (like salmon or tuna), walnuts, and flaxseed.

Unhealthy fats
Unhealthy fats are solid at room temperature. Examples include butter, coconut oil and shortening. The types of unhealthy fats include:

  • Saturated fats (unhealthy fats). Saturated fats raise blood cholesterol (fat levels in the blood). Saturated fats are solid at room temperature. They are found mostly in animal foods, such as butter, meat or cheese. Some vegetable oils also have saturated fat. This includes coconut, palm and palm kernel oil.
  • Trans fats. These are made when unsaturated fats become solid. Examples include margarine, vegetable shortening and processed foods with partially hydrogenated vegetable oil. Trans fats raise blood cholesterol levels should be avoided.

Did you know…?

The most important way to lower blood cholesterol is actually eating less saturated fat, not cholesterol, in your diet.

Tips to change the fats in your diet

Choose wisely

  • Choose lean chicken or fish more than red meats.
  • Pick leaner cuts of red meats.
  • Trim all the fat you see from food.
  • Limit high cholesterol foods like egg yolks and whole dairy products.
  • Limit foods labeled creamy, battered or fried.
  • When eating out, ask for no butter or gravy on the side.
  • Limit high-fat sweets, such as ice cream or baked goods. Instead, choose fresh fruit, Jell-O®, sherbet, low-fat yogurt or angel food cake.

Be prepared

  • Take the skin off the chicken or turkey before you cook. Most of the fat is in the skin or between the skin and meat.

Cook smart

  • Bake, broil, steam or microwave foods.
  • If you use fat to cook, pick the healthier monounsaturated fats like olive or canola oil.
  • Add flavor with herbs, spices, lemon or lime juice, salsa, mustard, garlic, seasoned vinegar or onion.

Red light foods

These are foods you should choose less often.

Breakfast, lunch and dinner

  • Pancakes or waffles with butter
  • High-sugar cereal with whole milk
  • Full-fat or full-sugar yogurt
  • Fried or roasted chicken with the skin
  • High-fat pork, beef, veal or lamb
  • Fried fish
  • Chili con carne
  • Salami, pastrami, pepperoni, hot dogs or sausage
  • Liver
  • Tuna in oil
  • Tacos with full-fat or high-fat toppings

Side dishes

  • Fried or sautéed vegetables
  • French fries or onion rings
  • Corn bread
  • Cream soups
  • Macaroni and cheese or pasta with alfredo sauce
  • Pizza
  • Lasagna
  • Caesar salad


  • Regular crackers
  • Taco shells
  • Movie popcorn
  • Potato chips or corn chips


  • Soda, sweetened drinks or fruit juice
  • Milkshakes

Desserts or sweets

  • Baked goods, such as biscuits, donuts, muffins, pastries, cake and cookies
  • Chocolate candy

Green light foods

These are foods you can choose more often.

Breakfast, lunch and dinner

  • Oatmeal, farina or high-fiber cereal with skim milk
  • English muffin
  • Grilled, roasted or baked chicken without skin
  • Sliced turkey breast, ham or roast beef
  • Beans
  • Tofu
  • Baked, grilled or steamed fish, such as tuna in water, sole or flounder
  • Taco salad without sour cream or guacamole

Side dishes

  • Low-fat yogurt
  • Part-skim cheese
  • Steamed or grilled vegetables or onions sautéed in oil
  • Baked, grilled, steamed or boiled potatoes
  • Soft roll or pita
  • Soup (not creamed)
  • Pasta with tomato sauce
  • Homemade pizza bagel with part-skim cheese
  • Salad with low-fat dressing or oil and vinegar


  • Low-fat, whole grain or whole wheat crackers
  • Tortillas
  • Air-popped popcorn
  • Baked chips
  • Pretzels
  • Matzoh


  • Water, low-fat milk, unsweetened drinks or teas

Desserts and sweets

  • Bialy
  • Jelly beans, hard candy or fruit snacks
  • Ginger snaps, graham crackers or low-fat cookies
  • Angel food cake

Rev. 4/2019. Reviewed by the MGfC Family Advisory Council. Images courtesy of Pixabay®. Mass General for Children and Massachusetts General Hospital do not endorse any of the brands listed on this handout. This handout is intended to provide health information so that you can be better informed. It is not a substitute for medical advice and should not be used to treatment of any medical conditions.