How Much Fat Should Be in Your Diet?

Tiffany Lester, MD
July 10, 2017

For decades, scientists and nutritionists have debated how much fat the average person should consume. The latest research suggests that fat is not the demon we once believed it to be, especially when it comes to increasing the risk of heart disease and high cholesterol. Still, with coconuts replacing kale as the darlings of the food world and the increasing popularity of the ketogenic diet , the question remains: Can you eat too much fat?

Before looking at the amount of fat in your diet, it’s important to understand that not all fat is created equal. You may see comparisons like saturated vs. unsaturated, omega-3 vs. omega-6, or monounsaturated vs. polyunsaturated. Even for the savviest among us, it can be very confusing.

What is Fat?

Fatty acids are the building blocks for all types of fat and are made of carbon and hydrogen atoms. They are often classified by length (or number of carbons) into short, medium, and long chain fatty acids or by the number of double bonds a fat has (mono or poly).

Saturated vs. Unsaturated Fat

Fatty acids that are liquid at room temperature are called unsaturated fat and tend to have more double bonds. Conversely, fatty acids that are solid at room temperature are called saturated fat and tend to have fewer double bonds. Unsaturated fats are largely derived from plants such as nuts, seeds, and olives, whereas saturated fats tend to come from animal products like pork lard, beef tallow, and butter, though they can also be found in certain plant sources like coconut and palm. Fats can also be a combination of the two. For example, coconut oil contains both saturated and unsaturated fat.

Unsaturated fats are further split into two categories: monounsaturated (olive oil, avocados, nuts) and polyunsaturated (grapeseed and safflower oil, fish). Monounsaturated fats have one double bond and contain only oleic fatty acid. Polyunsaturated fats contain more than one double bond and contain DHA and EPA, the fatty acids commonly found in fish oil.

Omega-3 vs. Omega-6 Fatty Acids

Omega-6 fatty acids are mostly found in processed foods and vegetable oil while omega-3 fatty acids are present in foods like walnuts, chia seeds, salmon, pasture-raised eggs, and flax seeds. The ratio of omega-3 to omega-6 fatty acids that you consume is more important than the actual amount of either in your diet. The optimal ratio is 4:1, with more omega-3 fatty acids in your diet. An imbalance in this ratio can cause inflammation and increase your risk for heart disease, cancer, and autoimmune disorders. Thus, increasing the amount of omega-3-rich foods in your diet can have a profound impact on lowering total body inflammation.

What About Trans Fats?

The fatty acids known as trans fats are made through a chemical process called hydrogenation which solidifies their oils to ensure a longer shelf-life in the grocery store. Trans fat promotes inflammation and is associated with increasing your risk for heart disease, stroke, metabolic syndrome, and diabetes. The best way to avoid trans fat is to steer clear of processed foods and any food that lists “partially hydrogenated oils” as an ingredient.

Moderation is Key

The question remains, how much fat should be in your diet? The truth is, there is no one size fits all answer; some people thrive on a high fat diet while others do not. What we do know, is that you can’t eliminate fat altogether. Fat is essential to overall health; the brain is made up of 60% fat and fat helps the body produce hormones, regulate fat storage, and absorb vitamins.

For each individual, the ideal amount of fat in his or her diet depends on factors like genetics, sex hormones, and activity levels. Most people should be getting at least 20-25% of their daily macronutrients from a variety of high quality fats. Whether it’s eating an avocado, drizzling olive oil over your salad, or cooking with ghee, you can easily reach this goal by making sure you include at least one type of healthy fat at every meal.

Regardless of how much fat you have in your diet, it is important to have regular diagnostic testing, as everyone metabolizes fat differently. At Parsley Health , we routinely test an individual’s complete cholesterol composition, particularly if consuming a high fat diet, to closely monitor these metabolic markers.

Tiffany Lester, MD

Dr. Tiffany Lester is a board-certified Integrative Medicine Physician who has practiced a holistic approach to health for over a decade. She is a graduate of the University of Cincinnati College of Medicine, where she completed her training in internal medicine. She also graduated from the Integrative Medicine Fellowship at the University of Arizona with Dr. Andrew Weil, and has extensive training in functional medicine through the Institute of Functional Medicine. Dr. Lester is also featured as a teacher for the Institute of Integrative Nutrition and regularly contributes to national wellness publications.

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