• Photo for Just Chewing the Fat? Learn the Good, Bad (and Ugly!) of Dietary Fat
    Photo Credit: iStockPhoto

Just Chewing the Fat? Learn the Good, Bad (and Ugly!) of Dietary Fat

By Beth Sumrell Ehrensberger, RD, MPH

Most people have a love/hate relationship with fat. On one hand, its velvety presence makes food practically melt in your mouth (think: a big bowl of homemade mac and cheese). On the other hand, it’s probably part of the reason your favorite pants keep getting “shrunk by the cleaners.”

Since the landslide of fat free products hit stores during the 90’s, it’s likely you’ve had had the opportunity to sample some of the less-than-palatable offerings. Cheese that does not melt? Definitely fat free. Salad dressing that leaves a thick, slick finish on your tongue? Unmistakably lacking in fat. But the funny thing about those fat free products is that the calorie difference between the slimmed down version and the original version is often quite slight. Take, for example, Fig Newtons: the original version has only 20 more calories and two grams of fat when compared to the fat-free version. That’s no diet bargain! (Though the fat free is still a better choice—read on to find out why.) And since many people mistake fat-free to mean a limit-free indulgence, it’s no wonder that our nation is in an obesity crisis. If you eat a couple of servings of even fat-free cookies, you’ll still be putting away too many calories, fat-free or not. The bottom line is, fat-free doesn’t always mean diet—and in fact, we need fat.

Even if you’re dieting to get rid of fat, it still belongs in your nutrition lineup—you just need the right kind and less of it. Fat is critical in aiding the absorption of fat soluble vitamins A, E, D, and K. If you’re not taking in enough fat, your body can’t use these vitamins to unleash their health benefits. Plus—and this probably comes as no surprise to you—though protein foods have the highest satiety level of the macronutrients (fat, carbohydrate, protein), fat follows closely behind. That’s why eating a meal that contains a bit of fat and lean protein helps you feel fuller than one that contains, for example, just carbohydrates. Think Egg McMuffin vs. bagel with jelly. Plus, the longer you feel full, the less tempted you’ll be to pick up extra diet-busting calories.

But even though fat is crucial to the body’s functioning, that’s not your license to butter up, dress up and smother up your food with fat. You don’t need to eat a lot of fat to get the benefits—and we’ll give you the lowdown of how much, and from where they should be coming.

The Bad Fats: Saturated and Trans Fat
These are the primary offenders in raising dietary cholesterol, which, in turn, increases the risk for coronary heart disease are trans and saturated fat. And if saturated fat is the Norman Bates of the fat world, trans fat is the Hannibal Lecter. It’s big trouble. Trans fat is the case of a good fat gone bad: it happens when hydrogen is added to innocuous monounsaturated or polyunsaturated oil to make it solid. Trans fat not only raises LDL (bad cholesterol), but can lower HDL (good cholesterol). Plus, trans fat is associated with an increased risk of developing type 2 diabetes. It doesn’t take much trans to make a train wreck: just by adding a mere four grams of trans fat to your diet, you increase your heart disease risk by 23 percent. Small amounts of trans fats are naturally occurring in some animal-based foods like beef, cheese and butter, but it’s widely found in fried foods, some margarines, and commercial baked goods.

You’ll have to look closely at the packages—even if a food brags “trans fat free” on the label, if partially hydrogenated vegetable oil is in the ingredient list, there are small amounts of trans fat that can that add up when you eat more than one serving. Remember those Fig Newtons? It turns out that the regular version, though the label lists trans fat as “0”, has trans fat hidden in them (there’s partially hydrogenated cottonseed oil in the ingredient list). Because the FDA allows foods that have up to 0.49 grams of trans fat per serving to be labeled as “0”, the Newtons get a trans fat pass. But eat a stack of Newtons, and you’re probably taking in much more trans fat than you’d consciously choose. Beware of tricky marketing, though; some food companies, wise that the public is concerned about trans fat intake, will take out the trans, and label accordingly, but replace it with other bad fats like saturated fat. So, even though the label might say “trans fat free” it could still be an artery clogging choice.

Saturated fat in excess is an express ticket for a trip to your local cardiologist—but it’s also linked to other diseases, such as cancer. Some research indicates that a diet that is high in saturated fat increases the risk for prostate cancer. Since our bodies make all of the saturated fat we need to function, there’s no need to willfully seek to add it to your diet, but because it’s in a lot of foods it’s impossible to totally avoid it. Saturated fat can be found in foods that come from animal sources like meat, dairy, and eggs, as well as a couple of plant-based sources like coconut and palm kernel oil. You already know foods that are high in saturated fat raise your LDL cholesterol—which increases your risk for heart disease and stroke—but the real kicker is that foods that are high in saturated fat are also high in cholesterol, and that makes for a fatty double whammy. To slash your intake of saturated fat, cut back on red meat and full-fat dairy products like cheese, and try swapping out red meat for chicken, beans and fish.

Aim for a combined 20 grams of saturated plus trans fat per day. And watch out—those numbers add up: order a Big Mac, and you’re more than halfway there.

The Good Fats: Monounsaturated & Polyunsaturated
Want to lower your LDL and total cholesterol? Make sure the fats you’re eating are either polyunsaturated or monounsaturated. These unsaturated fats, when used to replace saturated fat in the diet, can help improve blood cholesterol levels as well as quell inflammation and keep heart rhythms stable. And monounsaturated fats are the true foil to trans: they can help lower LDL and raise HDL cholesterols. Plus, a weighty bonus to relying on unsaturated fats, especially monounsaturated? Research suggests that a diet rich in monounsaturated fats can aid in weight loss.

If you’re used to adding butter to the pan to sauté veggies, make the switch to liquid vegetable oils like olive, canola, corn, sunflower and soy which are rich in monounsaturated or polyunsaturated fats. A good rule of thumb is to strive to let the bulk of the fat in your diet come from plant sources like avocados, nuts, seeds and fish that are high in omega-3 fatty acids. And what is all the fuss about omegas? Plenty deserved, it seems; studies show that this polyunsaturated fat can help everything from memory loss to cancer. Of omega-3 fats in particular, plan for one or more servings from this important group every day—fish, walnuts, canola or soybean oil as well as flax seeds (ground) are easy ways to slip a little good fat into your diet.

But just like everything, it’s all too easy to have too much of a good thing, and even though unsaturated fats can do your body good—a little dab will do ‘ya. Aim for a total fat intake between 25 and 35 percent of total calories.