Dietary fats are confusing.
There’s “good” fats and “bad” fats, fats you should put in your coffee, fats that will make you fat, fats that won't…
I like to thank (well... thanks, but no thanks) good ‘ole diet culture for creating this confusion. I was raised during the tail end of the low-fat craze - my adolescence was more so marked by the popular South Beach zero carb trends - but, as a Registered Dietitian, I’ve done my fair share of research into the diets that have shaped our weight loss culture.
My weight loss philosophy is centered on the idea that different strategies work for different people, but unless there is an underlying health condition that requires it, I don’t foresee myself recommending a low-fat diet solely for the purposes of weight loss to anyone… like, ever.
I cannot emphasize enough how important it is to incorporate healthy fats into your diet.
Fats slow digestion and help curb blood sugar response, increase absorption of fat soluble vitamins (A, E, D, K), minerals, and phytonutrients, serve as precursors for sex hormone production & regulation, and have anti-inflammatory and protective properties.
Otherwise put: Eat fats if you want to stay fuller for longer, have less cravings and lower levels of inflammation, and not be down for the count every time your monthly cycle comes around.
To answer a few questions I know are probably running through your mind...
Will eating fat make you gain weight?
No. Eating too many calories will make you gain weight.
If you eat fat before exercise will you burn more fat?
That’s also gonna be a no. The energy source you use during exercise depends on the duration and intensity of your workout. You’re always burning both carbs AND fat, no matter what, just in differing amounts.
What types of fats are found in food?
Here’s where I want to spend some time! It’s important to differentiate fat that is found in food, and the way that fat is stored in our bodies. We do need a minimal amount of essential fat that is required for normal physiologic functioning. Beyond that, most people also have “storage fat” in adipose tissue, which is an active endocrine organ that secretes hormones and stores excess energy (calories) as fat - to name just a few functions. This stored fat isn't necessarily bad, but in excess (more than about 30% body fat for females), it can increase your risk of, for example, cardiovascular disease.
Fat is found in our food in several different forms. I don’t want to get too scientific, but the differentiation lies in the molecular carbon/hydrogen structure of the fat molecule. Now, I’m sure the pamphlet at your doctor’s office has already made you very aware of the “bad” saturated and trans fats, and I prefer to focus on the good anyway, so let’s do that!
The "good" unsaturated fats can be identified as either monounsaturated or polyunsaturated (again, depending on their carbon/hydrogen makeup). There are two essential fatty acids of particular importance that humans must acquire from their diet: omega-6 polyunsaturated fatty acids and omega-3 polyunsaturated fatty acids.
Both Omega-6 and Omega-3 fatty acids are important precursors to other essential fatty acids in our bodies. Only plants contain the enzyme that is needed to produce Omega-6 and Omega-3 fatty acids, which explains why some of the best sources of omega-6 are vegetable (soybean, safflower and corn) oils, and why fish are rich in Omega-3 because their diet consists of the plankton plant.
Why do you need these in your diet?
I’ll give you a few good reasons! In addition to all of the general benefits of fat, these essential fatty acids offer something special. Omega-3’s in particular have a strong anti-inflammatory effect (remember this for later!). Other benefits include visual and neurological health (think: lower risk of Alzheimer's and other cognitive disease), as well as better blood cholesterol and blood sugar levels.
So, you’re still wondering, how much fat should you get?
I work with my clients to set daily nutrient targets that generally include ~35% total calories from fat, and suggest they include at least one source of fat at every meal. Remember just a few seconds ago when I mentioned Omega-3's having a strong anti-inflammatory effect? That's why it's important to get more of them! Now, not every single type of fat you eat has to be a source of Omega-3, but the problem that most people run into is eating too many pro-inflammatory foods and not enough anti-inflammatory foods to balance them out. Maybe you've heard about inflammation being a thing? Eating more salmon, chia seeds, walnuts, and roasted seaweed snacks is a great way to reduce inflammation in *your* body!