What Are Healthy Fats?
Fats are high in calories and have been linked to numerous diseases. So, how could any of them possibly be healthy? The answer lies in the many essential roles that fat plays in the body. Not all fats are created equal, and some are not just acceptable but necessary for optimal health.
What Does Fat Do in the Human Body?
Fat serves a wide range of critical functions, including:
• Providing a tightly packaged, efficient storage form of energy
• Supplying essential fatty acids that are vital for brain and nervous system health and functioning
• Absorbing fat-soluble vitamins (A, D, E, and K) and transporting them throughout the body
• Insulating and protecting vital organs
• Enhancing the flavor and palatability of food
• Promoting satiety (the feeling of fullness after eating)
• Supporting cell membrane function by regulating the flow of contents in and out of cells
• Serving as a building block for steroid hormones, including testosterone and estrogen, via cholesterol, which the body actually requires in appropriate amounts
What Are Fats, Exactly?
The fats we consume in our diets are called triglycerides, molecules made up of a glycerol backbone and three fatty acid tails. It’s those fatty acid tails that determine what type of fat it is: saturated or unsaturated.
Saturated fats have only single bonds in their fatty acid tails, while unsaturated fats contain one or more double bonds. Unsaturated fats can be further broken down into two categories: monounsaturated fatty acids (MUFAs), which have one double bond, and polyunsaturated fatty acids (PUFAs), which have multiple double bonds. The type of bonding matters because it directly affects how a fat interacts with and influences body processes.
Polyunsaturated Fatty Acids (PUFAs)
PUFAs are considered essential fats because the human body cannot produce them on its own. They must come from your diet. This category of fat has consistently shown beneficial effects on the body, playing key roles in muscle contraction and relaxation, blood vessel dilation and constriction, blood clot formation, blood lipid regulation, and immune response.
The two primary PUFAs we need are omega-3 and omega-6 fatty acids. Most Americans get plenty of omega-6. It is abundant in corn oil, which is a staple ingredient in much of the country’s food production.
Getting enough omega-3, however, requires a bit more intention. Common sources include fatty fish and marine algae and products derived from them. The good news is that just two servings of omega-3-rich fish per week are enough for most adults to meet their daily requirements. Because omega-3 is a fat, it is stored readily in the body; you don’t need to eat it every day.
How Much Fat Should I Consume?
In general, about 20–35% of your total daily calories should come from fats. Of that, less than 5% should come from saturated fats, and ideally more than half of your total fat intake should come from polyunsaturated fatty acids.
Calculating omega-3 intake is a bit more nuanced, as the recommendation is based on the amount of eicosanoids (signaling compounds derived from fatty acids) in a food source, rather than fat calories alone. This means you’ll want to check the specific eicosanoid content of foods you regularly eat.
Do I Have to Eat Only Polyunsaturated Fats?
Not at all. You can enjoy other forms of fat as part of a balanced diet, as long as you stay within your overall caloric goals. The key is to make sure that at least half of your total fat intake comes from polyunsaturated sources. Think of it as a foundation, not a restriction. Build your fat intake around PUFAs, and there’s room for other fats too.
