What You Need to Know About Fat
Get the Facts on Fat
For years, you might have heard that the best diet for your heart health was a low-fat diet. Then all of the sudden, it might have seemed as if the tables turned, and medical professionals started recommending some types of fat. A few diets that supposedly help people lose weight, such as the keto diet and other low-carb diets, tend to be high in fat.
So which is correct? A mix of both, it turns out. Your body needs fat to function properly. But some fats are better than others, and some are downright no good for you. Get to know the different types of fat and what you can do to build a healthy diet around them.
Fat is one of the three macronutrients. Along with protein and carbohydrates, your body needs fat to produce energy and to maintain the organs. Fat provides insulation, which helps you keep warm. It also helps you absorb vitamins D, E, K, and A1.
Your brain needs fat, particularly the essential fatty acids, linoleic and linolenic acid. Fatty acids also help to minimize inflammation and improve blood clotting.
Fat falls into two main categories, saturated and unsaturated. Saturated fats are usually solid at room temperature. Unsaturated fats remain liquid. Whether unsaturated or saturated, all types of fat have nine calories per gram. It's what they do in the body that sets them apart.
Trans fat is a type of unsaturated fat that has been processed so that it remains solid at room temperature. There is also naturally occurring trans fat, which is produced by animals and found in dairy and meat.
Simply stated, trans fat is best avoided, as it offers no health benefits and increases the risk of heart disease2. Trans fat also raises levels of LDL (aka the "bad") cholesterol in your blood while lowering HDL (aka the "good") cholesterol.
Artificial trans fats have been banned in the US since 20183. However, some foods might still contain a small amount of trans fat, particularly if they are animal products. Always check the nutrition label to see how much, if any, trans fat food contains.
Saturated fat can also raise your risk of heart disease and raise LDL levels in your blood. Although saturated fat often gets called a "bad" fat, it's found in any food that contains fat, so it's not something you can avoid entirely.
What you can do is limit the amount of saturated fat you take in. The American Heart Association recommends getting no more than 6% of your daily calories from saturated fat. If you eat a 2,000 calorie diet, that's about 13 grams of saturated fat daily4.
While saturated fat is found in any food that has fat, some foods have more than others. Beef and whole-fat dairy products contain higher amounts of it, as do plant oils from tropical plants, such as coconut and palm oils.
Monounsaturated fat is one of the "good" fats. It helps to lower levels of LDL cholesterol while raising levels of HDL. Many types of vegetable oils, such as canola and olive oil, are good dietary sources of monounsaturated fats. Nuts, seeds, and avocados are also good sources.
Polyunsaturated fat is another type of "good" fat. Like monounsaturated fat, polyunsaturated helps to lower your LDL cholesterol levels while raising HDL levels.
Certain types of essential fatty acids, such as omega-3 and omega-6, are types of polyunsaturated fats. Your body needs these fats but can't produce them on its own, so you need to get them from your diet.
Vegetable oils such as olive, canola, and sunflower oils are all good sources of polyunsaturated fats. Soybeans, tofu, and walnuts are also good sources. Fatty fish, such as salmon, are great sources of omega-3 fatty acids.
How Much Fat Should You Eat?
The American Heart Association recommends eating unsaturated fats in moderation5, avoiding trans fats, and limiting saturated fats.
What that might mean in practice is limiting how much full-fat dairy and red meat you eat to one or two servings daily and focusing on getting your dietary fat from plant-based sources, such as olive oil and avocados.
If you're concerned about your heart health or cholesterol levels, your family doctor can help you put together an eating plan that focuses on healthy fats and heart health.
1. Dietary fat explained, Medline Plus, https://medlineplus.gov/ency/patientinstructions/000104.htm
2. Facts about trans fat, Medline Plus, https://medlineplus.gov/ency/patientinstructions/000786.htm#
3. Artificial trans fats banned in U.S, Harvard, https://www.hsph.harvard.edu/news/hsph-in-the-news/us-bans-artificial-trans-fats/
4. Saturated fat, American Heart Association, https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/saturated-fats
5. Monounsaturated fat, American Heart Association, https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/monounsaturated-fats