Dietary Fats: Which Ones to Choose

Facts about fat: why you need it

We get dietary fat from foods and beverages we consume (different from what our bodies store, such as belly fat). Dietary fat is one of three macronutrients, along with protein and carbohydrates, which we need in larger quantities because they provide us with energy. Fat also supports cell growth, protects organs, produces hormones, and helps the absorption of fat-soluble vitamins (1). 

Low-fat diets

Fat is more energy-dense (contains more calories) in comparison to carbohydrates and protein. This is why low-fat diets are one way to decrease total calories. Expending more calories than we take in can help with weight loss. 

We need some dietary fats in our diet. Healthy sources of dietary fat can also be more satiating, meaning they help keep you full (2). Scientific research suggests that diets high in fat do not appear to be the main cause of excess body fat (3). 

High-fat, low-carbohydrate diets 

High-fat, low-carbohydrate diets such as the keto diet have been gaining popularity as a quick weight loss method. The concept is that focusing on fats while reducing carbohydrates and protein can help reduce hunger. 

Just keep in mind that since it's restrictive, it may not be for everyone. If you’re curious about trying high-fat, low-carbohydrate diets, learn more here: A Beginner’s Guide to Doing Keto

Importance of fat quality

Not all fats are created equal. There are four main types in the foods we eat: saturated fats, trans fats, monounsaturated fats, and polyunsaturated fats. These all have different structures and can have different impacts on your body. 

Focus on these healthy fats

The healthiest types of fats are monounsaturated and polyunsaturated. For good health, the majority of the fats you eat should be these ones instead of saturated or trans fats. 

Monounsaturated fats 

Monounsaturated fats can help lower the unhealthy type of blood cholesterol. This can help reduce the risk for heart disease and stroke (4). Monounsaturated fats also provide nutrients such as vitamin E which is an antioxidant helpful for preventing age-related disease. 

• Sources: nuts, olives, olive oil and other plant oils (canola, safflower, sunflower), avocados.  

Polyunsaturated fats 

Polyunsaturated fats include omega-3 and omega-6. These are both essential, meaning that we have to get them from our diet. 

Omega-3s have powerful effects on the heart, brain, and body. Getting more omega-3 can help lower triglyceride levels, decreasing the risk for heart disease. Omega-3 are also vital for good brain function and development and have been suggested to improve mood (5).

Omega-6 fats are also beneficial because they can help lower harmful types of blood cholesterol (LDL) while increasing healthy types (HDL). Since most Americans eat about 10 times more omega-6 than omega-3, it's important to make sure to get a balance by focusing on more omega-3 sources. 

• Omega-3 fatty acids: oily fish (salmon, sardines, mackerel), nuts and seeds (chia and walnuts), plant oils (flaxseed oil) (5). 
• Omega-6 fatty acids: nuts and seeds (walnuts, pumpkin seeds, sunflower seeds), plant oils (safflower oil, sunflower oil, soybean oil). 

Moderate these fats

Saturated fats 

Saturated fats are best consumed in lower amounts. Eating a lot of saturated fats, especially if you have high cholesterol or diabetes, can increase your risk for heart disease (1). Aim for less than 7% of your daily calories coming from saturated fat and try to switch food sources for monounsaturated and polyunsaturated fat sources (6). 

Saturated fats are solid at room temperature. It's better to get them from natural sources instead of packaged sources. 

• Natural sources: red meat, pork, full-fat dairy, coconut. 

• Processed sources: desserts, baked goods (cakes, cookies, donuts, pastries), sausages, hot dogs. 

Avoid or limit these fats

Trans fats

Trans fats are considered to be the unhealthiest type you can eat. They raise harmful cholesterol (LDL) while lowering the helpful kind (HDL). Trans fats are man-made. Food manufacturers add hydrogen to oil, to make it solid at room temperature. This helps extend the shelf life. 

In the United States, if a food has less than 0.5 grams of trans fat per serving, they can label it as 0 grams of trans fat (7). The best way to check if a food contains trans fat is to look at the nutrition label. If you see “partially hydrogenated” oils, this means it contains some trans fat. Aim for less than 1% of your total daily calories from trans fat (6). 

• Sources: packaged snacks, baked goods (cakes, cookies, pies, donuts), fried foods, non-dairy creamer, some peanut butter and margarine.

How to choose healthier fats

For overall health, it is good to swap the less healthy fats for the healthy ones whenever possible. Focus on adding more of the monounsaturated fats (nuts, olives, avocado) and polyunsaturated fats (oily fish, chia seed, walnuts) with less saturated fats (meat, eggs, desserts, baked goods) and no to few trans fats (fried foods, packaged snacks and pastries).

In addition, it is important to eat a balanced diet full of whole foods that emphasizes lots of fruits, vegetables, whole grains, low-fat dairy, lean protein (fish, poultry, beans), and nuts and seeds while limiting red meat and processed foods that contain added sugar, salt, and fat. 

Want a diet that is super healthy fat-friendly? Try the Mediterranean diet on the Lifesum app.