Healthy Fats vs. Unhealthy Fats: Understanding the Differences

healthy fats

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We usually associate fat in foods with fat around our waistline. However, these two are not necessarily intertwined.

Fats play an important role in our body, providing energy and aiding in the absorption of certain vitamins. However, not all fats are created equal. Some can be beneficial for our health, while others can have harmful effects. In this article, we'll explore the differences between healthy fats and unhealthy fats, and how they impact our overall health.

What are Fats? 

healthy fats

Fats are a type of nutrient that our body needs to function properly. They are essential for the absorption of fat-soluble vitamins, such as vitamins A, D, E, and K. Fats also provide our body with energy, insulation, and protection for our vital organs.

What are Healthy Fats?

Healthy fats are monounsaturated and polyunsaturated fats that can help reduce the risk of heart disease and stroke. They can improve insulin sensitivity, reduce inflammation, and support brain health. Healthy fats also aid in the absorption of fat-soluble vitamins and provide the body with essential fatty acids, which it cannot produce on its own. Foods high in healthy fats include avocados, nuts, seeds, fatty fish, and olive oil.

Healthy fats, such as monounsaturated and polyunsaturated fats, are different from unhealthy fats, such as saturated and trans fats, in their chemical structure and impact on the body. Healthy fats have a higher ratio of unsaturated fatty acids, which have at least one double bond in their carbon chain. This double bond makes the fat more flexible and fluid, allowing it to move more easily through the bloodstream. In contrast, unhealthy fats have a higher ratio of saturated or trans fatty acids, which have no double bonds or are partially hydrogenated, respectively. These types of fats are more rigid and solid at room temperature, making them more difficult to transport through the bloodstream and potentially leading to health problems.

Additionally, healthy fats have been shown to have a positive impact on cholesterol levels, reducing the risk of heart disease and stroke. Research has shown that monounsaturated fats, particularly those that come from oleic acid and olive oil, can decrease the risk of heart disease. Monounsaturated fats can be found in olive oil, canola oil, multiple different kinds of nuts, and avocados. 

heart healthy fats

When it comes to being heart-healthy, polyunsaturated fats may be even better than monounsaturated fats. Polyunsaturated fats are prevalent in vegetable oils and seed oils. By replacing saturated fats with polyunsaturated fats, we can reduce our risk of heart disease by up to 19%. Omega-3 fatty acids are a particular type of polyunsaturated fat that has been shown to be beneficial in reducing the risk of heart disease. Omega-3 fatty acids have received a good amount of attention from the media, and for good reason.  Omega-3’s are not only great for our heart, but also an important part of our cell membranes, inflammatory response, and help to regulate the hormones responsible for blood clotting. They are commonly found in seafood like salmon, tuna, and herring. It should be noted that the US Food and Drug Administration and Environmental Protection Agency cautions against large consumption of fish due to the possibility of high mercury concentrations. While different types and sizes of fish contain varying amounts of mercury, keeping fish consumption below two or three servings weekly is considered safe. If you’re not a seafood person, flaxseed, chia seeds, walnuts, avocados, and soybeans are also great sources of omega-3 fatty acids.

Overall, incorporating healthy fats into the diet, such as those found in avocados, nuts, seeds, fatty fish, and plant-based oils, can have numerous health benefits compared to consuming unhealthy fats found in processed foods.

What are Unhealthy Fats?

Unhealthy fats include specific types of saturated and trans fats that can increase the risk of heart disease and stroke. They can also contribute to insulin resistance, inflammation, and other health problems. Foods high in unhealthy fats include processed foods, fried foods, and fatty meats.

Unhealthy fats include trans fats and some saturated fats. One of the qualities that makes these fats unhealthy is the lack of double bonds. In this way, saturated fat is a more stable molecule. This is why saturated fats are solid at room temperature. The result is a molecule that is difficult to transport through the bloodstream.

The length of the saturated fat molecule and the number of carbon atoms also play a role in determining whether or not a fat is healthy. While further research is needed, the current literature suggests that very long fats (meaning they contain 22 or more carbon atoms) may actually decrease the risk of type 2 diabetes.

Besides some saturated fats, trans fats can also be unhealthy.  Trans fats are man-made fats that are created by infusing vegetable oil with hydrogen gas in a process called hydrogenating. They are commonly found in processed foods such as fried foods, baked goods, and margarine.

Consuming too much of these unhealthy types of fats has been linked to an increased risk of heart disease, obesity, and other health problems. It is recommended to limit the intake of unhealthy fats and focus on consuming healthy fats from sources such as nuts, seeds, fish, and avocados.

The Impact of Fats on Blood Sugar and Insulin 

fat intake and blood sugar

Unhealthy fats can contribute to insulin resistance, which can lead to high blood sugar levels and an increased risk of type 2 diabetes. Part of the association between unhealthy fats and poor blood sugar regulation is due to the other ingredients present in foods that contain saturated and trans fats. In the American diet, 15% of the saturated fat intake comes from high-carbohydrate desserts like candy and baked goods. A second 15% of saturated fat is consumed through fast food like burgers, pizza, and fries. These foods are not only high in saturated fat but also calorically dense. Additionally, the baked goods and candy have a very high sugar content, which we know is harmful to our blood sugar control and metabolic health.  

On the other hand, healthy fats can improve insulin sensitivity, which can help regulate blood sugar levels and reduce the risk of type 2 diabetes. Healthy fats have been found to have a positive impact on blood sugar and insulin regulation. Studies have shown that including healthy fats in the diet can help improve insulin sensitivity and reduce the risk of developing type 2 diabetes.

One reason for this is that healthy fats can slow down the absorption of carbohydrates, which can help prevent rapid spikes in blood sugar levels. They also help promote feelings of fullness, which can reduce the overall amount of food consumed and help with weight management. Additionally, some healthy fats contain compounds that have anti-inflammatory properties, which may play a role in improving insulin sensitivity and reducing inflammation in the body.

It's important to note that while healthy fats can have benefits for blood sugar and insulin regulation, they should still be consumed in moderation as part of a balanced diet. Consuming too much of any type of fat can lead to weight gain and other negative health outcomes.

Incorporating Healthy Fats into Your Diet 

7 healthy fats

Incorporating healthy fats into your diet is important for maintaining overall health. Some easy ways to do this include using olive oil instead of butter or margarine, snacking on nuts and seeds, and eating fatty fish, such as salmon, twice a week.

The American Heart Association recommends that healthy fats should make up between 25-35% of your daily calorie intake. This can vary depending on your age, gender, weight, and physical activity level. As a general guideline, aim to consume two to three servings of healthy fats per day, such as one serving of avocado or a handful of nuts. It's important to remember that while healthy fats can provide many health benefits, they are also high in calories, so it's essential to consume them in moderation as part of a balanced diet. It's always a good idea to speak with a healthcare professional or registered dietitian to determine the appropriate amount of healthy fats to include in your diet.

Here are some examples of healthy fats:

  1. Fatty fish (such as salmon, tuna, herring, and mackerel)
  2. Nuts (such as almonds, walnuts, and pistachios)
  3. Seeds (such as chia, flax, and pumpkin seeds)
  4. Avocado
  5. Olive oil

The Skinny on Fats 

what are healthy fats

Understanding the differences between healthy fats and unhealthy fats is important for maintaining optimal health. Replacing saturated and trans fats with healthy fats can reduce the risk of heart disease by up to 25%. Incorporating healthy fats into the diet, such as those found in avocados, nuts, seeds, fatty fish, and plant-based oils, can decrease insulin resistance and help reduce the risk of stroke and type 2 diabetes.


Author: Dr. Colleen Gulick