By Franziska Spritzler, RD, CDE
Fat is an important part of your diet, but figuring out how much to eat can be confusing. Over the last 50 years, everyday diets have gone from moderate-fat to low-fat, based on recommendations from health organizations. However, the 2015–2020 US Dietary Guidelines no longer specify an upper limit for how much total fat you should consume. This article takes a detailed look at different types of fat and provides suggestions for how much to eat per day.
What Is Fat?
Along with protein and carbs, fat is one of the three macronutrients in your diet. You consume fat in the form of triglycerides. A triglyceride molecule is made up of three fatty acids attached to a glycerol backbone. The fatty acids contain chains of carbons and hydrogens. One way fats are classified is by the length of their carbon chains:
- Short-chain fatty acids: Fewer than 6 carbons.
- Medium-chain fatty acids: 6–12 carbons.
- Long-chain fatty acids: 13–21 carbons.
- Very-long-chain fatty acids: 22 or more carbons.
Most of the fats you eat are long-chain fatty acids. Short-chain fatty acids are mainly produced when bacteria ferment soluble fiber in your colon, although milk fat also contains small amounts. Long-chain and very-long-chain fats are absorbed into the bloodstream and released into the body’s cells as needed. However, short-chain and medium-chain fats are taken up directly by the liver to be used as energy.
Bottom Line: Fats are one of the three macronutrients. They are absorbed from food and used by the body for energy and other functions.
Functions and Benefits of Fat
Fat performs a number of functions and provides several health benefits:
- Energy: Fat is an excellent energy source. It provides 9 calories per gram, whereas protein and carbs each provide 4 calories per gram.
- Hormone and gene regulation: Fats regulate the production of reproductive and steroid hormones, as well as genes involved in growth and metabolism.
- Brain function: Adequate fat intake is important for brain health, including mood.
- Absorption of fat-soluble vitamins: Vitamins A, D, E and K must be consumed with fat to be properly absorbed.
- Flavor and fullness: Adding fat to foods makes them tastier and more filling.
The fat stored inside your body helps insulate your organs, keeps you warm and provides a vast source of energy that you can use in the case of famine.
Bottom Line: Fats provide a number of benefits for your body, including serving as an energy source, regulating hormones and genes, maintaining brain health and making food more tasty and satisfying.
Different Types of Fat
Fatty acids are grouped according to the number of double bonds between carbons in their structures.
Monounsaturated fatty acids (MUFAs) have one double bond in their carbon chains. MUFA food sources are typically liquid at room temperature and fairly stable for cooking purposes. The most common MUFA is oleic acid, which olive oil contains in high amounts.
Monounsaturated fat is linked to several health benefits, including a reduced risk of serious diseases such as heart disease and diabetes. One review of 24 controlled studies found diets in monounsaturated fat lead to significantly lower blood sugar, triglycerides, weight and blood pressure, compared to high-carb diets. They also increased HDL (“good”) cholesterol levels. MUFAs may also increase feelings of fullness that lead to reduced calorie intake. In one study, people felt fuller and took in fewer calories for the next 24 hours after consuming bread rich in oleic acid, compared to bread that contained less.
Polyunsaturated fatty acids (PUFAs) contain two or more double bonds. They can be divided into groups depending on the location of the double bonds. These include omega-3s and omega-6s. These double bonds make PUFAs more flexible and fluid than saturated fats.
On the other hand, they’re also far more prone to damage and rancidity. Studies have found that long-chain omega-3 fats have benefits for inflammation, heart disease, diabetes, depression and other health conditions. Although you need some omega-6 fats, they can be inflammatory when consumed in excess, especially if omega-3 PUFA intake is low. Omega-6 fats are very common in modern-day diets. On the other hand, omega-3 fats are usually consumed in much smaller amounts. Significantly, researchers report that the evolutionary diet of humans provided a ratio of omega-6 to omega-3 fats between 1:1 and 4:1. By contrast, it’s estimated that most people now consume these fats in a 15–17:1 ratio.
Saturated fatty acids (SFAs) have no double bonds in their carbon chains, so the carbons are said to be “saturated” with hydrogen. They are very stable at high temperatures and far less likely to be damaged during cooking than polyunsaturated fats. SFA intake can raise LDL (“bad”) cholesterol levels in some people, although this depends in part on the specific fatty acids consumed. It should also be noted that HDL cholesterol typically goes up as wel.
Overall, research indicates that SFA consumption has a neutral effect on health and doesn’t appear to cause or contribute to heart disease. In fact, some foods high in saturated fat may benefit metabolic health. For example, studies suggest that the medium-chain triglycerides in coconut oil and palm oil may boost metabolic rate and reduce calorie intake.
In a trans fats molecule, hydrogens are positioned across from each other rather than side by side. Small amounts of trans fats occur naturally in dairy and other animal foods. However, nothing is natural about the trans fats used in processed foods. These trans fats are produced by adding hydrogen to unsaturated fats to create a product that functions more like a saturated fat. Ingredient labels often list them as “partially hydrogenated” fats.
Consuming trans fats can lead to a number of health problems. Artificial trans fats are linked to inflammation, unhealthy cholesterol changes, impaired artery function, insulin resistance and excess belly fat. One study estimated that replacing trans fat with other fats could reduce heart disease risk by up to 40%, depending on the type and amount of fat substituted. Trans fats are often found in margarine and other processed spreads. Food manufacturers sometimes add them to packaged products such as crackers to help extend shelf life.
Bottom Line: Fats are grouped by the number of bonds in their carbon chains. Aside from trans fats, most fats have beneficial or neutral effects on health. However, a high omega-6 to omega-3 ratio may cause problems.
How Much Fat Is Healthy to Eat Per Day?
The appropriate amount of fat to eat will depend on your calorie requirements for weight loss or maintenance. It will also be based on your eating style and diet. You can use this calculator to determine your calorie needs to lose weight or maintain your weight. This is your daily calorie goal.
A standard low-fat diet contains about 30% of calories from fat, or less. Here are a few examples of suggested daily fat ranges for a low-fat diet, based on different calorie goals:
- 1,500 calories: About 50 grams of fat per day.
- 2,000 calories: About 67 grams of fat per day.
- 2,500 calories: About 83 grams of fat per day.
It’s important to note that studies show higher-fat diets, such as low-carb and Mediterranean diets, are actually much healthier than the standard low-fat diet.
High-Fat Low-Carb or Ketogenic Diet
A ketogenic diet minimizes carbs, provides a moderate amount of protein and is high in fat. The percentage of calories from fat will depend on how low your carb intake is, but it will generally be between 50–75% of calories. Here are a few examples of suggested daily fat ranges for a low-carb or ketogenic diet, based on different calorie goals:
- 1,500 calories: About 83–125 grams of fat per day.
- 2,000 calories: About 111–167 grams of fat per day.
- 2,500 calories: About 139–208 grams of fat per day.
Moderate-Fat Mediterranean Diet
The Mediterranean diet includes a wide variety of plant and animal foods such as fish, meat, eggs, dairy, extra virgin olive oil, fruits, vegetables, legumes and whole grains. It typically provides 35–40% of calories from fat, including plenty of monounsaturated fat from olive oil.
Here are a few examples of suggested daily fat ranges for a Mediterranean diet, based on different calorie goals:
- 1,500 calories: About 58–67 grams of fat per day.
- 2,000 calories: About 78–89 grams of fat per day.
- 2,500 calories: About 97–111 grams of fat per day.
Bottom Line: How much fat you eat per day should be based on the type of diet you follow and your calorie needs for weight loss or maintenance.
Foods High in Healthy Fat
Regardless of the type of diet you follow, it’s important to get a balance of different types of healthy fats every day. Fortunately, many delicious foods can provide the fat you need. While most foods contain a mixture of different fats, some are especially high in certain types.
Below are examples of foods rich in different types of healthy fats.
Monounsaturated fats are found in most plant and animal foods, but some foods are especially rich in them.
- Olive oil
- Macadamia nuts
All of these foods also contain omega-6 polyunsaturated fats.
Omega-6 fats are present in most plant and animal foods, including those mentioned above. However, getting adequate omega-3 fats takes a little more work.
Foods rich in omega-3s include:
- Chia seeds
Healthy foods that are high in saturated fat include:
- Coconut oil
- Palm oil
- Whole-milk dairy, such as full-fat yogurt
- Mascarpone cheese
- Cheddar cheese
- Lamb meat
Bottom Line: Choose a variety of healthy foods that provide fats from each of the different groups every day, especially omega-3 fats.
Take Home Message
Fats serve a number of important functions, along with making foods taste better and helping you feel satisfied. Fortunately, a rather large range of fat intake is actually considered healthy. Eating the right amounts and right types of fat can go a long way toward reducing disease risk and enhancing your overall health.
This article is reprinted with permission from Authority Nutrition.