Fats 101: The Difference Between Healthy and Unhealthy Fats

Clinical Dietitian
Friday, June 16, 2017 - 3:02pm

Remember in the 90s when eating fat-free foods was the rage? The grocery store shelves were stocked with fat-free cookies, cakes, ice cream – you name it! Those were the days when many people thought that eating fat made you fat. Thankfully though, the field of nutrition has recovered from this misunderstood fat-phobia due to more recent research that has shown certain types of dietary fat can actually improve our health and lower the risk for heart disease. 

Check out these key facts about each type of fat:

Trans Fat 

This is a type of fat that occurs naturally in some foods in small amounts. Most trans fats are made from oils through a food processing method called partial hydrogenation. Foods containing trans fats are more stable, which means the food products they’re added to will last longer on supermarket shelves. Unfortunately, these are also the worst offenders when it comes to our health. Trans fats have been shown to not only to increase unhealthy low-density lipoprotein (LDL) cholesterol but also to lower health high-density lipoprotein (HDL) cholesterol, which can increase the risk of cardiovascular disease. A great way to decrease trans fat intake is start reading ingredient lists. Avoid foods containing “partially hydrogenated” ingredients; it’s code for trans fat! Common foods containing partially hydrogenated oils are baking mixes, commercial baked goods, as well as some margarine, lard and fried foods.

Saturated Fat 

Saturated fat, which is solid at room temperature, is most often found in animal products such as red meat and full-fat dairy products. Plant sources of saturated fat include coconut oil and palm oil. But, it’s the animal-based saturated fats that we should be most concerned about having a negative effect on health. Saturated fats have been found to raise total blood cholesterol levels and LDL cholesterol levels, which can increase the risk of cardiovascular disease. 

Monounsaturated Fatty Acids (MUFAs) and Polyunsaturated Fatty Acids (PUFAs)

MUFAs and PUFAs are liquid at room temperature and are found in many vegetable and fish-based foods. Studies show that eating foods rich in monounsaturated fats and polyunsaturated fats improve blood cholesterol levels, which can decrease your risk of heart disease. Research also shows that monounsaturated fats may benefit insulin levels and blood sugar control, which can be especially helpful if you have type 2 diabetes. Polyunsaturated fats may also help decrease the risk of type 2 diabetes. Examples of monounsaturated fats include certain oils (olive, canola, peanut, sesame, safflower), avocados, peanut butter and many nuts and seeds. Examples of polyunsaturated fats include soybean, corn, sunflower oil, ground flaxseed, fatty fish like salmon, mackerel, herring and trout. Other sources include some nuts and seeds, such as walnuts and sunflower seeds, tofu and soybeans. 

Omega-3 Fatty Acids 

One type of polyunsaturated fat is made up of mainly omega-3 fatty acids and may be especially beneficial to your heart. Omega-3 fatty acids may decrease triglycerides, lower blood pressure slightly, reduce blood clotting, decrease stroke and heart failure risk and reduce irregular heartbeats. Fish is the main source of the heart disease-fighting omega-3 fats eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but some plant-based foods also contain omega-3 in the form of alpha-linolenic acid (ALA), which also helps heart health. Fatty fish, such as salmon, trout, mackerel, herring, sardines and tuna contain the most omega-3 fatty acids. Plant-based sources of omega-3 fatty acids include flaxseed, chia seeds, walnuts, soy foods and pumpkin seeds. 

Stay tuned for ten tips and food swaps to help you eat more healthy fats and less unhealthy fats.