For something that tastes so delicious and gives us so much pleasure, fat is plenty confusing.
Most of us remember too well the “fat phobia” of the ‘80s and ‘90s, when eating low-fat/no-fat was deemed the one true way to lasting weight loss. The result? Few of us lost weight or kept it off, though we scarfed plenty of processed foods that may have been fat-free but were full of empty calories (often sugar).
“Eliminating or reducing one entire food group is never a good idea,” cautions Abbie Gellman, R.D., culinary nutritionist and owner of Culinary Nutrition Cuisine, in New York City. “When you cut back on fat, that leads to increased consumption of carbohydrates and protein … A diet too high in refined carbohydrates can be as unhealthy as a high-fat diet because it increases the risk of diabetes and heart disease and other cardiac issues.”
Then, inevitably, the fear-of-fat pendulum swung the other way: Eating more fat (and protein) was trumpeted as the only way to lose weight. This time “carb” replaced “fat” in the low/no-is-best contest. Even if you don’t cringe at carbohydrates anymore, it’s still often hard to know what you should eat, both for weight loss and good health.
These days, fat is once again at the center of the same debate. A new book, Eat Fat, Get Thin: Why the Fat We Eat is the Key to Sustained Weight Loss and Vibrant Health, by Dr. Mark Hyman, a best-selling author and director of functional medicine at the Cleveland Clinic[i], is helping to put fat back in the spotlight. “Eating more fat is the single best thing you can do to lose weight, feel good, live longer and even prevent conditions ranging from heart disease and cancer to type 2 diabetes and dementia,” says Hyman in a video on his website. Even saturated fat isn’t to blame for what’s making us fatter and sicker, he asserts; it’s sugars and carbs[ii] that are the true culprits.
Hyman isn’t a lone voice these days in re-asserting the importance of fat. A January 2016 study in the Journal of the American Heart Association[iii]estimated that nearly 50,000 Americans die annually as a result of eating too little of certain vegetable oils that help protect the heart. The authors of the study say that while there has been plenty of emphasis on getting people to reduce their intake of unhealthy trans and saturated fats, there’s been too little focus on eating enough of the healthy kinds of fat our body needs every day. (Since fat has 9 calories per gram, compared to 4 for protein or carbs[iv], it could be that our fat phobia is lingering a little more than we may realize…)
It’s worth knowing that many types of fat aren’t just good for you, they’re 100% necessary[v]. “We all need fat in our diet,” echoes Gellman. “Nutritionally, fats supply calories, texture, satiety [a feeling of fullness and satisfaction], and essential nutrients.” Your body needs fat from the foods you eat to function properly: It gives you energy; it’s key to healthy hair and skin; it helps insulate your body; and essential fatty acids (the ones found in greatest amounts in fish and fish oil) are hugely important to how your eyes, heart, and brain function. Adds Gellman: “The fat in our diet also helps us absorb certain fat-soluble vitamins—A, D, E, and K. A very low-fat diet makes you less likely to absorb these vitamins, which can impact immunity and bone health,” among other bodily functions.
“Nutritionally, fats supply calories, texture, satiety [a feeling of fullness and satisfaction], and essential nutrients.”
–Abbie Gellman, R.D.
Specifically, we need foods with monounsaturated fat[vi] (good food sources: many seeds and nuts, avocados, canola oil, olive oil, peanut oil) and especially polyunsaturated fat[vii] (salmon, herring, mackerel, trout, tofu and other soy products, walnuts). The saturated and trans fats are the ones most experts say we should limit, since they’re thought to contribute to elevated levels of LDL (the so-called “bad”) cholesterol. Saturated fats come mostly from animal products, and both saturated and trans fats are listed on food labels, so they aren’t hard to avoid when you’re picking up groceries.
When in doubt, keep it simple, suggests Gellman: “The best meals and snacks include a mix of protein, fiber, and healthy fats; this combo will keep you full for at least three hours and prevent blood sugar dips that can affect mood.”