If you think about it, there’s kind of a nice symmetry to it. Too much body fat is bad — it contributes not only to a jiggly physique but also to a whole slew of really nasty chronic illnesses. And where could that excess body fat come from besides eating large amounts of fatty foods? That right there has essentially been the basis of American nutritional policy for decades. Symmetry aside, it’s not strictly true.
Want proof? Look at France. Boasting brie and any number of amazing buttery pastries (think: croissants, palmiers and éclairs) and sauces (velouté, hollandaise, bechamel, we’re looking at you), the French diet consists of a lot of fat, particularly saturated fat, and yet the French population has among the lowest rate of heart disease of any industrialized country in the world. It’s not just association, either. There was a lot of poorly executed science decades ago, the results of which fueled ideas like the concept that dietary fat intake raises cholesterol levels, and cholesterol causes heart disease. It’s not as simple as that, and scientists are still trying to unwind all the influences of diet and disease, but one thing is clear: Eating more fat, as long as it’s the right kinds, is not detrimental to health. In fact, it’s required for optimal health.
Your Body on Fat
The term “fat” encompasses several different types — some unhealthy, others healthy and the overall majority, essential. In the body, fats serve both structural (they’re responsible for the stiffness of cell membranes) and metabolic (fueling the heart, among other organs) functions. And while a fat is a fat, there are three main types — saturated, unsaturated and trans — that vary in chemical structure and benefit. For example, while synthetic forms of trans fats like those found in processed foods are unanimously regarded as unhealthy, natural trans fats, which are only slightly different structurally, have been shown to affect the body in dramatically different and incredibly beneficial ways. Studies have shown that consumption of industrial trans fats can negatively impact cholesterol levels and increase the risk of heart disease, cancer and obesity; the risk of these very same diseases can be reduced by consuming natural trans fats. One natural trans fat, conjugated linoleic acid (CLA), has even been shown in clinical studies to reduce fat stores, particularly in the abdomen, and can be taken as a supplement. A fat that burns fat — now that’s irony.
Trans fats certainly aren’t alone when it comes to discrimination. Perhaps it’s their solid consistency that made scientists assume saturated fats contribute to clogging arteries, but despite clear evidence that many beneficial and essential types of saturated fats exist, there remains an overall negative perception plaguing mainstream media and nutritional policy. Saturated fats are characteristically solid at room temperature because their chemical structure allows each fatty acid to pack tightly against another. While unhealthy saturated fats do exist (in grain-fed meats and Oreos, for example), they cannot be unjustly lumped into the same category as those found in coconut oil and grass-fed animal products. Saturated fat has several critical roles within the body — it’s largely responsible for tissue integrity, comprising roughly half of cell membrane structure, and it augments immune function, suppresses inflammation, facilitates communication between cells and is critical to hormone production. As if that’s not enough, saturated fat is a critical building block for brain cells and is otherwise required for proper nervous system function.
Meanwhile, unsaturated fat tends to benefit from a more benign outlook but it too has less-healthy varieties (which promote inflammation) and others that are known to exert healthy, anti-inflammatory properties. There are two main types of essential polyunsaturated fatty acids, omega-6 (inflammatory fats) and omega-3s (anti-inflammatory fats). While both types are essential, meaning the body doesn’t produce them on its own and must get them from the diet, omega-6 fats are ubiquitous in everyday foods and most Americans could afford to consume less of them. On the other hand, fish-oil supplementation remains advisable because most people consuming a Western diet get insufficient omega-3 fats. When considering your consumption of these fats, ratio is everything. Maintaining an appropriate balance of omega-6s to omega-3s is critical because the machinery involved in metabolizing each is shared; consequently, an excess of one type can interfere with the metabolism of the other type. Your target ratio of omega-6 to omega-3 should be about 2:1 to 3:1. Anything above 4:1 is considered problematic. Alarmingly, the ratio of the average American diet has been reported to reach as high as 15:1.
Another class of unsaturated fats, monounsaturated fats, differ from polyunsaturated fats in that they only contain a single point of unsaturation, or one double bond. Because double bonds are more susceptible to oxidation, monounsaturated fats (which have fewer double bonds than polyunsaturated fats) are more stable and less likely to oxidize. (Oxidation of fats is kind of analogous to rusting of metal; it’s detrimental to your cells.) For this reason and because they’ve been shown to improve cholesterol levels and even increase insulin sensitivity, thereby reducing the risk of diabetes, monounsaturated fats — think olive oil, nuts, seeds and avocado — are almost unanimously touted as healthier fats that everyone should consume.
Adding Fats to Your Menu
Fat is the most calorie dense of the three macronutrients, packing 9 calories per gram compared with 4 calories per gram for carbohydrates and protein. And because nothing in nutrition is ever simple, experts have been arguing for decades over the ideal ratio of these three macronutrients when it comes to optimizing performance, weight management and overall health. The magic appears to depend on what type of sport you pursue, because explosive activity is best done with some carbohydrates to burn, whereas those who engage primarily in endurance activity can rely almost exclusively on fats. Of course, CrossFit complicates all this by including both types of training — often in the same WOD. However, it is certainly true that carbs are easiest for the body to burn, and if blood sugar is high, excess fat will be stored; when it’s low, stored body fat will be burned for energy.
Fortunately, there are some basic guidelines we can impart. The most basic is to absolutely and resolutely avoid synthetic trans fats, derived from hydrogenated vegetable oils and found in processed foods. They were developed by food scientists looking to keep baked goods shelf stable for longer, and they work wonders — but not on your arteries. The Food and Drug Administration recently found that partially hydrogenated oils are not “Generally Regarded As Safe” and has given food manufacturers three years to remove them from their products. In the meantime, make sure you read ingredients labels and be aware that “partially hydrogenated” means that product is guaranteed to contain industrial trans fats. And keep in mind, in the U.S., companies are allowed to list anything less than 0.5 grams of trans fat per serving as 0 grams of trans fat on the Nutrition Facts label. Though that might seem like a trivial amount, if you eat multiple servings of these foods — exactly what they’ve been strategically designed to make you do — the amount you’re ingesting adds up.
Unlike synthetic Frankenfats, naturally occurring trans fats are formed in the stomachs of ruminant animals (like cows). During digestion of grasses, the animal’s gut bacteria convert the polyunsaturated fats in grass to rumenic and vaccenic acid. Rumenic acid, or CLA, can be obtained from eating grass-fed meat and dairy products that contain about three to five times the amount of CLA found in grain-fed animal products. Grass-fed animal products also contain healthy saturated fats. If you’re looking to increase your intake of beneficial fats, remember to choose cuts of meat with higher ratios of fat — i.e., trade your sirloin for a rib-eye.
Whole-fat dairy from grass-fed animals is another great source of saturated fat and CLA. Analyses have shown that cheeses from grass-fed cows were significantly higher in total CLA content compared with conventional and even organic cheese. The healthiest part of dairy is likely the fat and the fat-soluble vitamins A, D and K2 it offers. Therefore, if you do not have autoimmune issues and can tolerate dairy, you would likely benefit from consuming high-quality whole-fat products like butter, yogurt and cheese from grass-fed cattle.
One of the most remarkable advantages to eating grass-fed meat is the unsaturated fatty-acid profile they offer. Cattle fed grass reportedly produce beef with an omega-6:omega-3 fatty-acid profile of 2:1 to 3:1, compared to 15:1 to 20:1 for grain-fattened beef. You can almost think of swapping grain-fed beef for grass-fed beef as being similar to converting a conventional hamburger into an omega-3-rich wild Alaskan salmon fillet. A study published in 2011 in the British Journal of Nutrition showed that individuals who ate a grass-fed red-meat diet for four weeks improved their plasma ratios of essential fatty acids from 9:1 to 6:1, compared with those on a diet of red meat from animals fed concentrate, whose ratios worsened from 8:1 to 13:1.
Wild fatty fish and pastured eggs are also top sources of omega-3 fats. A study from Penn State’s Dairy Cattle Research and Education Center reported that eggs from pastured hens had twice as much long-chain omega-3 fats, two-and-a-half times more total omega-3 fats, and less than half the ratio of omega-6:omega-3 fats compared to eggs from caged hens. And while flaxseed and chia seeds do offer omega-3 fats in the form of alpha-linolenic acid, the body does a poor job converting this to docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the forms it most benefits from and which are readily available in fish oil.
Another common source of fats is vegetable and seed oils. However, pick wisely; many of these — including sunflower, corn, soybean and cottonseed — boast dreadfully high concentrations of omega-6 fats and should be avoided entirely. Canadian rapeseed oil, commonly disguised as canola oil, also should be limited if consumed at all. Because of their biochemical structure, these types of unsaturated fats are unstable when heated and should not be used for cooking. Monounsaturated fats — and saturated fats to an even greater extent — are more suitable for use in cooking because of their more stable biochemical structures. Healthy sources of monounsaturated fats include olives and olive oil, avocados and avocado oil, and macadamia nuts and macadamia-nut oil. The healthiest source of plant-derived saturated fat appears to be coconut, which is a one-stop shop that provides oil for cooking, milk for drinking and mixing into recipes, and “meat” for eating.