Dietary fats: Know which types to choose
When choosing fats, pick unsaturated fat over saturated fat. Here's how.By Mayo Clinic Staff
You don't need to eliminate all fat from your diet. In fact, some fats actually help promote good health. But it's wise to choose the healthier types of dietary fat and then enjoy them as part of a balanced diet.
The facts about fat
There are numerous types of fat. Your body makes its own fat from taking in excess calories. Some fats are found in the foods you eat — these are called dietary fats. Dietary fat is a macronutrient that provides energy for your body.
Fat is essential to your health because it supports a number of your body's functions. Some vitamins, for instance, must have fat to dissolve so that they can be used by your body.
But some types of dietary fat are thought to play a role in cardiovascular disease. In addition, fats are high in calories, so you need to balance your fat intake against the other foods you eat so that you don't take in more calories than you need. If you eat more calories than you need, you will gain weight. Excess weight is linked to poor health.
Research about the possible harms and benefits of dietary fat is always evolving. Current evidence suggests that the smart play is to focus on choosing healthier fats and avoiding the less healthy ones.
There are two main types of potentially harmful dietary fats:
- Saturated fat. This type of fat comes mainly from animal sources of food, such as red meat, poultry and full-fat dairy products. Saturated fats raise high-density lipoprotein (HDL or "good") cholesterol and low-density lipoprotein (LDL or "bad") cholesterol levels, which may increase your risk of cardiovascular disease.
- Trans fat. This type of fat occurs naturally in some foods in small amounts. But most trans fats are made from oils through a food processing method called partial hydrogenation. These partially hydrogenated trans fats can increase total blood cholesterol, LDL cholesterol and triglyceride levels, but lower HDL cholesterol. This can increase your risk of cardiovascular disease.
Most fats that have a high percentage of saturated fat or that contain trans fat are solid at room temperature. Because of this, they're typically referred to as solid fats. They include beef fat, pork fat, butter, coconut oil, shortening and stick margarine.
The potentially helpful types of dietary fat are primarily unsaturated fats:
- Monounsaturated fatty acids. This type of fat is found in a variety of foods and oils. Studies show that eating foods rich in monounsaturated fatty acids instead of saturated fats improves blood cholesterol levels, which can decrease your risk of heart disease and may also help decrease the risk of type 2 diabetes.
- Polyunsaturated fatty acids. This type of fat is found mostly in plant-based foods and oils. Evidence shows that eating foods rich in polyunsaturated fatty acids instead of saturated fats improves blood cholesterol levels, which can decrease your risk of heart disease and may also help decrease the risk of type 2 diabetes.
- Omega-3 fatty acids. One type of polyunsaturated fat is made up of mainly omega-3 fatty acids and may be especially beneficial for heart health. Omega-3, found in some types of fatty fish, appears to decrease the risk of coronary artery disease. There are plant sources of omega-3 fatty acids. However, it hasn't yet been determined whether replacements for fish oil — plant-based or krill — have the same health effects as omega-3 fatty acid from fish.
Foods made up mostly of monounsaturated and polyunsaturated fats are liquid at room temperature, such as canola oil, olive oil, safflower oil, peanut oil, sunflower oil and corn oil.
Fish high in omega-3 fatty acids include salmon, tuna, trout, mackerel, sardines and herring. Plant sources of omega-3 fatty acids include flaxseed (ground), oils (canola, flaxseed, soybean), and nuts and other seeds (walnuts, butternuts and chia seeds).
Recommendations for fat intake
Because some fats are potentially helpful and others are potentially harmful to your health, it pays to know which ones you're eating and whether you're meeting recommendations.
The 2015-2020 Dietary Guidelines for Americans offers the following recommendations about fat intake:
- Avoid trans fat.
- Limit saturated fat to less than 10 percent of calories a day.
- Replace saturated fat with healthier monounsaturated and polyunsaturated fats.
How can I start eating healthier?
Focus on replacing foods high in saturated fat with foods that include monounsaturated fats and polyunsaturated fats.
Try these tips to make over the fat in your diet:
- To avoid trans fat, check food labels and look for the amount of trans fat listed. By law a serving of food containing less than 0.5 grams of trans fat can be labeled as 0 grams. Therefore, it's important to also check ingredient lists for the term ʺpartially hydrogenated.֞
- Use oil instead of solid fats. For example, saute with olive oil instead of butter, and use canola oil when baking.
- Prepare fish, such as salmon and mackerel, instead of meat at least twice a week to get healthy omega-3 fatty acids. Bake or broil seafood instead of frying it.
- Choose lean meat and skinless poultry. Trim visible fat from meat and poultry, and remove skin from poultry.
- Snack smart. Many popular processed snack foods are high in fat, especially solid fats. Be sure to check food labels for saturated and trans fats. Better yet, snack on whole fruits and vegetables.
Keep in mind that most foods contain a mix of different kinds of fat and varying levels of each type. Don't get bogged down in the details. Instead, focus on choosing foods that contain unsaturated fats, instead of foods that contain saturated or trans fats. For example, canola oil contains some saturated fat but is mostly a monounsaturated fat. It's a great replacement for butter, which contains some unsaturated fat but is mostly a saturated fat.
Don't go to extremes
All fats, including the healthy ones, are high in calories. To control your calorie intake, consume monounsaturated and polyunsaturated fats instead of other types of fat, not in addition to them.
If watching fat content is a good strategy, is it even better to try to eliminate all fat from your diet? No. First, your body needs some fat — the healthy fats — to function normally. If you try to avoid all fat, you risk getting insufficient amounts of fat-soluble vitamins and essential fatty acids.
Also, in attempting to remove fat from your diet, you may wind up eating too many processed foods touted as low-fat or fat-free rather than healthier and naturally lower fat foods, such as fruits, vegetables, legumes and whole grains. Instead of doing away with fat in your diet, enjoy healthy fats as part of your balanced diet.
Feb. 01, 2019
See more In-depth
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