Fat is one of the three major nutrients in food; the others are carbohydrates and protein. We need fat to help us use fat-soluble vitamins, which are important for healthy skin and hair. The fats we take into our bodies also help regulate body temperature and protect our organs, and our bodies use them to produce various hormones for the body.
Too much fat in our eating plan, however, is not healthy. Excess fat in our diet can increase cholesterol levels, add extra calories, and increase insulin resistance.
"Good" versus "bad" fats
Some of my clients recently asked me about "good fats" and "bad fats." I always hesitate to use these adjectives when talking about food, though, because food doesn’t really have any moral qualities; it just is. What we eat and how much we eat, however, may be healthy or not healthy, harmful or protective.
Not all fats are alike
There are different kinds of fats, with those differences being related to their chemical structures. Some fats may increase cholesterol levels, and this of course is not healthy for your heart. Other types may have a neutral effect on cholesterol, or help lower levels. And yet all these fats have the same amount of calories by volume and weight (1 teaspoon of fat—or 5 grams—contains 45 calories).
The main kinds of fat, and what each does inside us
Saturated fats are the principal type found in meats, poultry, seafood, bacon, cream, cheese, and dairy products. Plant sources of saturated fat are coconut and palm oil. Eating an excess amount of saturated fat may increase cholesterol levels. To reduce your intake of saturated fat, limit your portions of meat to the size of the palm of your hand (3 or 4 oz.), eat lean cuts of meat, trim off any extra fat, and buy low-fat or fat-free cheeses and dairy products (milk, yogurt).
Trans-fats may also increase cholesterol levels. They are created when liquid vegetable oil is solidified (an artificial process) and are found (although increasingly rarely now) in commercial baked goods and processed crackers and snacks. Our intake of this type of fat should be zero. Avoid buying foods that list hydrogenated oils or trans-fat on the label.
Unsaturated fats. There are 2 kinds of unsaturated fats.
- Monounsaturated fats may help lower LDL ("bad") cholesterol, the type of cholesterol that may increase your risk of heart disease. They may, however, also raise HDL ("good") cholesterol, which is a type of cholesterol that helps your body get rid of excess cholesterol. Main sources of monounsaturated fats are canola, olive, and peanut oils, avocados, and olives. Use these oils when you cook at home, and add avocados to sandwiches and salads.
- Polyunsaturated fats. These fats also help lower LDL-cholesterol and raise HDL-cholesterol. They are found in corn, safflower, sunflower, and sesame oils and are used in soft margarines.
Omega-3 fatty acids can help reduce inflammation in the body and protect against heart disease. They are found in flaxseeds, walnuts, and fatty fish like tuna, salmon, mackerel, sardines, and herring. Try to eat something containing omega-3 fatty acids three or four times a week.
We need some fat in our diet
Small amounts of fat can be part of a healthy eating plan. They add flavor to our foods and also help provide satiety (the feeling of being full or satisfied with the meal we have just eaten). If 25 percent to 30 percent of your total calories for the day come from fat, then your fat intake is reasonable. For a 1,500-calorie meal plan, that would be 40 to 50 grams of fat a day. Check the total fat content on food labels and learn which foods are highest in fat (i.e., greater than 5 grams of total fat per serving) and which ones have less.
Find the Fiber
Fiber is a food substance found in grains, fruits, and vegetables that our bodies can’t digest completely. Eating foods with fiber is part of a healthy eating plan and can help promote weight loss, healthy cholesterol levels, better blood glucose levels, and regular bowel movements. There are 2 different types of fiber: water-soluble fiber can be dissolved in water; water-insoluble fiber can’t.
- Once in the stomach, this type of fiber forms a gel that slows digestion and helps us feel fuller.
- May help reduce LDL-cholesterol levels.
- Found in oats, oat bran, dried beans and legumes, apples, oranges, pears, and flaxseeds.
- Increases bulk in the intestines and helps prevent constipation.
- Found in wheat and other grains like bulgur, couscous, barley, and corn, as well as in wheat bran, grapes, and potato skins.
What are the best sources of fiber?
- High-fiber cereals contain 6 grams (g) to 14 g of fiber per 1/2 cup portion. Eat this cereal in the morning, or else crush it up and sprinkle it on top of salads and casseroles.
- When they are cooked, dried beans, split peas, and lentils have 6 g to 8 g of fiber in every 1/2 cup.
- Whole grains, fruits, and vegetables contain 2 g to 3 g per portion. Aim for 5 servings of fruits and vegetables every day.
- High-fiber snack bars each have 8 g to 12 g of fiber.
How much fiber do I need?
Fiber is measured in grams. Most Americans eat an average of 10 g to 15 g of fiber every day in the foods they consume. The Dietary Guidelines for Americans, however, recommend that we each have 25 g to 30 g of fiber each day. If you are coming up short in the fiber department, start slowly adding small amounts of fiber to your meals; increase your fiber consumption slowly, to prevent problems with gas. Also, drink plenty of fluids to help the fiber move smoothly through your system.
If you adjust your pre-meal insulin based on how many grams of carbohydrate you are eating, you can subtract half the grams of the fiber in your meal (if it’s more than 5 grams) from the total grams of carbohydrate in that meal. Fiber is part of a healthy eating plan—find the fiber and enjoy!