Alright, buttercup, let’s chat about dietary fat today. There’s a whole lot to this topic and I’m not going to cover all of it here. If you’re looking for information about the potential benefits of coconut oil or low-carb, high fat diets like Atkins or a ketogenic diet, you won’t find it in this particular post, though I’ll add it to the list for a future date! We’re starting a little more basic today.
Types of Dietary Fat
Let’s start as basic as the different types of fat that we may consume. If you feel comfortable with this topic, jump on down to the next section.
So the types of fat in food might be saturated, monounsaturated, or polyunsaturated, and all foods are going to be a combination of all three, not strictly one or the other. There’s also trans fat, a yucky beast that we want to avoid at all costs.
Trans fats were an idea cooked up by food scientists that actually change the molecular structure of a fatty acid and seemed to extend the shelf life of fats and helped make them more profitable for the big food companies. Turns out, they actually do act differently in the body than fat from natural sources. (Kind of an example of why any new food innovations are regarded with a good amount of skepticism, like GMOs.) Look for the words “hydrogenated” or “partially hydrogenated” on your ingredient label. If you find one or the other, put the item down and find an alternative.
So saturated fats are found in things that are solid at room temperature. Most come from animal sources – butter, cheese, the fat in milk (the pieces are just really small and dissolved in the liquid), and the fat that you find throughout your meat. There are also some saturated fats that come from plant sources, like coconut oil or cocoa butter. Saturated fat is also the fat that’s been demonized by the health industry for increasing our risk of heart disease. But we’ll get to that in a bit.
The biggest sources of unsaturated fats in our diet (both mono- and poly-) are oils. Their chemical structure makes them liquid at room temperature. Olive oil, canola oil, peanut, sunflower, safflower, avocado, corn, soybean, cottonseed… Eating unsaturated fats has been associated with lower levels of LDL cholesterol (the bad type of cholesterol).
The category of polyunsaturated fats can be broken down even further into omega-3 and omega-6 fats. Omega-3s are the really good ones, the ones associated with lowering triglyceride levels in our blood, in helping with arthritis-related joint pain, depression, asthma, ADHD, Alzheimer’s. The ones from fish, walnuts, and flax seeds.
Omega-6s aren’t bad, but we tend to eat too many of them. A high ratio of omega-6 to omega-3 fats is being investigated as being detrimental to our health. Unfortunately, these are the types of fat found in corn oil, soybean oil, and cottonseed oil – all of which are found in large amounts in the standard American’s diet because they’re the cheapest to use and processed foods are full of them. They’re also likely from GMO plants and take high levels of chemical extraction to actually make – do you think of corn as generally being an oily food? I don’t. So where does corn oil come from? High levels of chemical processing. Yuck.
Dietary Fat and Our Health
I’ve read a lot of articles about dietary fat throughout my graduate studies and my general take away has been that the concern about dietary fat intake is the association between intake and weight gain and disease risk. If you eat well (eat mostly real, whole foods that you prepare yourself), are physically active, are maintaining a stable weight that YOU are happy with or if you are trying to gain weight, and if you are in good health (as stated by your doctor, not just “I feel fine”) then you keep doing you, sunshine, and good on ya.
However, if you are overweight and/or actively trying to lose weight, have been told you’re at risk for developing CVD or diabetes (i.e. have been told by your doctor that you have high cholesterol, high triglycerides, or are insulin resistant, etc.), or have been diagnosed with CVD or diabetes then the amount and type of fat you are eating and drinking becomes a lot more important to consider.
Fat itself is necessary to be able to absorb vitamins A, D, E, and K, conveniently known as the fat-soluble vitamins. Technically, our bodies make enough saturated fat that we don’t actually need to get any of that through food. The 2015 Dietary Guidelines for Americans (DGA) recommends limiting our saturated fat to less than 10% of our total calorie intake. If you’re a standard American and eat 1800-2000 calories a day, limit your saturated fat to 180-200 grams per day. But who wants to actually calculate that out?
So according to the DGA, the biggest sources of saturated fat in America’s diets are meat, poultry, and seafood dishes, grains and baked dishes (pre-made snack cakes or baked goods), and combination dishes that have meat or cheese or both – pizza! tacos! burgers! All of the delicious and addicting things in life. And when companies create a low-fat version of these foods they end up just replacing the fat with refined grains and sugar, which isn’t good for us either. But again, I’ll get to that in a minute.
As I mentioned above, foods tend to have a combination of different types of fat. Yes, the fat in butter is mostly saturated fat but it also has mono- and poly-unsaturated fats. Saturated fat actually raises both HDL and LDL cholesterol levels in the blood, that’s both the good and the bad types of cholesterol, so it’s possible that the overall effect equals out and it ends up being neutral. Scientists have yet to give a definitive answer. Perhaps more importantly, it’s the big, fluffy type of LDL cholesterol that increases due to eating saturated fat. LDL cholesterol molecules can either be big and ‘fluffy’ or small and dense. It’s actually the small, dense type of LDL that is really bad for us. Because they’re dense, they’re more likely to ‘sink’ out of our flowing blood and accumulate on our artery walls forming plaques and narrowing our arteries, increasing our risk of heart attack and stroke. They’re also more likely to be oxidized and lead to chronic inflammation. And higher levels of small, dense LDL cholesterol has been associated with higher intakes of carbs and added sugar. You see, when people cut back on fat they tend to replace it with carbs like bread and pasta instead of protein, fruits, and vegetables.
But if we replace foods that are high in saturated fat with foods that are high in unsaturated fat, it’s been shown that total cholesterol levels actually improve and the proportion of small, dense LDL cholesterol decreases, both of which lessen our risk of heart disease. Plus there’s strong evidence that we’re less likely to have a heart attack if we replace saturated fat with unsaturated fat in our diets.
Notice I say ‘replace’ not ‘add unsaturated fat’ in our diets. The health benefit comes from the actual swap. We don’t generally want to increase our overall fat intake, fat is the most calorie-dense macronutrient. Increased fat intake means increased calorie intake. We want to swap butter, lard, and shortening for things like olive oil and avocado oil when we cook. (Although baking is a whole other matter… Messing with the fat in baked goods will screw up the actual chemical reactions that happen and I don’t recommend it.)
One way to increase your intake of unsaturated fat in your diet is to invest your money in better meat and dairy. Grass-fed animals actually produce higher levels of omega-3 fats throughout their life, so the fat found in beef, butter, or milk from grass-fed cows will have a higher proportion of omega-3 unsaturated fat to saturated fat. Plus they’re treated better and just generally live healthier lives. It’s worth the increased cost! Healthier animals, healthier us!
And don’t worry, I don’t want to completely take your butter away from you. Just save it for times that it can enhance the flavor of a dish. Melt a tablespoon to pour over your (otherwise unflavored) popcorn for your at-home movie night. Enjoy it on your whole grain toast with breakfast. Add a pat to your baked potato. Sauté your vegetables in olive oil, bake your chicken with avocado oil, and save your butter for a time that you’ll actually notice it and the flavor it adds to a dish.
So if you’re still cooking your meals with butter, lard, or shortening start swapping those out for healthier oils like olive and avocado.
Save the butter for when you can really appreciate the flavor like on top of a baked potato or popcorn.
Don’t replace fat with carbs. Fat still has health benefits – it’s needed to be able to absorb and use certain vitamins, for joint health, brain health, and fighting inflammation.
High intake of refined carbohydrates actually has a negative effect on our cholesterol levels and heart health.
Bottom line – I don’t want you to replace fruits and veggies with a marbled steak with a nice pat of butter on top. But please don’t buy processed foods claiming to be low-fat thinking that it will be healthier for you. If you really want a croissant, eat a real flakey, buttery croissant. You’ll enjoy it much more and walk away satisfied. Maybe just don’t eat them every single day. You will be much better off eating grass-fed meat and dairy, enjoying full fat dairy and butter when they add significant quality to a dish, and eating lots of healthy fruits and vegetables to round out your plate.
Ending the War on Fat (originally published in TIME)