Know the Fats: Types and Impacts of Fat in Food

By Heather L. Dyson

The word “fat” comes with quite a few negative connotations, but what is fat really? Is it the root of all our weight gain problems? Is it the detriment of otherwise healthy Americans everywhere? Does it have any benefits? With so much conflicting information out there, it can be difficult to determine what role fat plays in a healthy diet and its negative effects. Let’s unpack some of the common conceptions to get to the bottom of fat and its functions. 
First and foremost, fat is an essential part of every diet. It is 1 of 3 macronutrients needed by the body to perform a range of functions, such as protecting organs, providing energy, supporting cell growth, and absorbing vitamins and minerals (1). Fat also plays an integral role in maintaining adequate cholesterol and blood pressure levels, and serves as a critical part of the brain’s learning and memory functions (1). So if fat can do all of this, why is it often labeled as bad? 

Fat is actually broken down into different categories based on their effects on the body. There are 3 primary types of fats: unsaturated, saturated, and trans. These fats all fall on a spectrum of health ranging from good to bad, so it is important to understand which ones are which to keep your body happy. 

Unsaturated fat at its simplest is the “good” fat that is found in nutrient-dense foods such as avocados, seeds, nuts, and fish. It is also found in dairy and nondairy foods like yogurt, milk, and eggs. These unsaturated fats are broken down into either Omega-3 or Omega-6 fatty acids, which are fatty acids that cannot be made within the body (2). These provide essential structural support and have anti-inflammatory effects. The  biggest impact of unsaturated fats is their ability to lower bad cholesterol (LDL) and promote good cholesterol (HDL), which is critical in keeping arteries free from plaque build-up (3). 

Saturated fats are not inherently bad and naturally occur in many foods. In fact, animal products are quite high in saturated fat, including chicken, beef, pork, eggs, and milk. Saturated fats are also found in plant-based foods and commonly used in the form of oil, such as coconut oil, palm oil, and olive oil. While these foods can be part of a healthy diet, it is important to be mindful of how much saturated fat you are consuming overall each day. Diets higher in saturated fat have been linked to higher levels of bad cholesterol, which contributes to poor cardiovascular health and the development of certain heart diseases (4). 

Finally, trans fat is a highly processed and modified fat that has been banned in the United States and many other countries. This fat is found primarily in fried foods and baked goods, though it can exist in small amounts in meat and dairy products. Trans fat also contributes to an increase in bad cholesterol and can even contribute to risk of stroke and the development of type 2 diabetes. The ban on trans fat is not absolute though; U.S. regulations actually permit trace amounts of trans fat as long as they are less than 0.5g per serving. This isn’t to say that you should be fearful of 0g trans fat labels, but just be mindful of the way the food may have been prepared so you can consume adequate servings to prevent unhealthy intake of these fats. 

It can be a lot to track, but as a general rule the best thing to do for your health is to simply limit the amount of saturated and trans fat you are consuming as much as possible. By sticking to the right serving sizes and eating foods with less than 1g of saturated fat, you can feel confident you are not increasing your chance of disease later on. With good fats, you will want to figure out your daily needs to ensure you are giving your body the right amounts. You can always explore your personal nutrition needs with a nutrition coach, which is a service coming soon to STAC! 
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1. N.A. (April 19, 2021). Know the facts about fats. Harvard Health Publishing. 
2. Higdon, J. (2003). Essential Fatty Acids. Oregon State University. 
3. McDermott, A. (March 24, 2022). What’s the Difference Between HDL and LDL Cholesterol? Healthline. 
4. N.A. (November 1, 2021). Saturated Fat. American Heart Association. 
5. N.A. (March 23, 2017). Trans Fat. American Heart Association.