I always feel like Dr. Seuss when I bring up the topic of fats. He has “One fish, two fish, red fish, blue fish” and I have good fats, bad fats, saturated fats and trans fats. Unfortunately, the majority of the population believes fats are responsible for our expanding waistlines, when really the culprit may primarily be sugar, with fat coming in at a close second. For some reason, we all have it engrained into our brains that if we completely cut out fat from our diets, all of our weight would just fall off. And who hasn’t tried it? While you do lose weight, it never has long-term success and there’s a reason why it doesn’t work. We actually need fats, and no it’s not the same as needing chocolate - we actually can’t live without them…well without some of them.
Fat is one of three macronutrients (along with carbohydrates and protein) that are the basic and essential components of every diet. They are integral in many of the biological processes that keep you going every day. For example, they provide essential fatty acids, deliver fat-soluble vitamins (vitamins A, D, E and K), and are an extraordinary source of fuel. The USDA recommends we get 20-35% of our calories from fat, and we need at least 10% of our calories to come from fat in order to maintain homeostasis. But that 20-35% should come from good fats, not bad ones. Here is the skinny on fats, how to avoid the artery-clogging trans fats and how to incorporate the heart healthy omega-3 fatty acids.
I bet you think consuming 20-35% of your calories from fat is absurd, but actually Americans over consume fats every day. On average, around 40% of our calories come from fat and you probably don’t even realize it - they hide in many of the foods we eat all the time like steak, cheese, processed foods, and sweet desserts. As I mentioned above, over consuming fat is yet another piece of the equation that leads to obesity, which soon triggers a slew of obesity-related disease such as type 2 diabetes, certain cancers (breast and colon cancer in particular) and heart disease.
Before we get into good versus bad, there is one thing you should know. All fats have the same number of calories, regardless if they are good or bad. This macronutrient is the most calorically dense at 9 calories per gram (carbohydrates and protein come in at 4 calories per gram and alcohol has 7 calories per gram), so it pays to proceed with caution on the amount of fat you’re consuming, even if you stick to good fats. This translates into weight loss if you cut back on all types of fat in your diet as well as a longer and healthier life.
Let’s take a step back and look at the big picture, the simplest way to categorize fats is in two groups: unsaturated (good) and saturated (bad). However I think that trans (evil) fats lend themselves into a category all their own. So we have the good, the bad and the evil. Let’s start with the good guys…
The Good Guys
Unsaturated fats are what people are referring to when they say “good” fats. There are many subdivisions within unsaturated fats but we are going to keep it simple - this isn’t biochemistry. Within unsaturated fats you have polyunsaturated (PUFAs) and monounsaturated (MUFAs). Both, when eaten in moderation and in substitution of bad and evil fats may help lower cholesterol levels and reduce your risk for coronary heart disease. PUFAs help lower blood cholesterol and triglyceride levels, and the attention grabbing omega-3 fatty acid is actually a PUFA (polyunsaturated fat). Omega-3s are known for their potential heart-health benefits and are found in fatty, oily fish (salmon, trout), nuts (walnuts) and seeds (flaxseed). PUFAs are also found mostly in vegetable oils and plant sources. Omega-3’s have such a beneficial impact on your heart that the American Heart Association recommends two servings of healthfully prepared fatty fish each week (no not deep fried fish and chips). MUFAs (monounsaturated fats) are thought to reduce the risk of heart disease and are primarily liquid at room temperature and solid when refrigerated. They are good sources of vitamin E and can be found in many oils (olive, canola), nuts (almonds) and fruits and vegetables (avocado).
The Bad Guys
Saturated fats can raise cholesterol levels, clog arteries and increase your risk for heart disease. They are primarily found in animal products (meat, butter, poultry skin) and are liquid at room temperature when they come from vegetables (coconut oil). It is recommended to keep your daily caloric intake from saturated fats below 7%.
The Evil Guys
Trans fats have been, rightfully, targeted as the all-encompassing demon responsible for America’s obesity epidemic and declining health. They increase your risk for heart disease (the number one killer in America) by increasing bad (LDL) cholesterol and decreasing good (HDL) cholesterol, which leads to clogged arteries. There are actually two types of trans fats, the naturally occurring ones that are found in small amounts in meat and dairy, and the artificial kind that were accidentally created by Wilhelm Normann in 1911, and are solid at room temperature. These artificial trans fats were once unsaturated fats that underwent a man-made chemical conformational change when liquid oils are hardened into “partially hydrogenated” fats. Due to their long shelf life and extremely inexpensive cost, they have shown up in everything - every processed food, fried food, packaged snack foods, microwave popcorn and even some margarines - and are worse for you than lard.
So how do you choose the good, and avoid the bad and the evil? It’s as easy as reading a label. Check the nutrition panel that is required to be on every packaged food in your grocery store. Avoid anything with partially hydrogenated oils (check the ingredient list) and only choose foods whose labels explicitly state 0g trans-fat. Opt for whole foods such as whole grains, fruits, vegetables and beans/legumes, and low-fat or skim dairy options. And remember, even when consuming good fats, do so in moderation.