Can good fats make you slim?
Olive oil or butter? Whole or skim milk? ELLE dishes on the latest from the experts.
Our diet-crazed culture has a habit of falling hard for half-truths. Several years ago, it was “Cut out the fat and lose the weight,” a claim that had us scrutinizing the labels of every package of food. If we managed to completely remove the three-letter word from our diet, we felt like champions. Oils were the first to go, then avocados, followed by nuts and eggs. Not getting the weight-loss results we wanted, we turned a critical eye on carbohydrates and repeated the familiar pattern, swapping our “low-fat” and “fat-free” products with “low-carb” or “carb-free” ones.
But now, with the demise in popularity of the Atkins low-carb diet, we’ve come full circle and are cautiously eyeing fats again. Perhaps the biggest lesson we learned while testing all those famous low-fat diets, like Scarsdale and Pritikin, was that total elimination is not the answer to our health and diet goals. “In the last 20 years, we’ve all been raised to believe in low fat, low fat, low fat — like all fat is evil,” says Melanie Rozwadowski, an assistant professor at the University of Saskatchewan’s College of Pharmacy and Nutrition. The body needs monounsaturates and polyunsaturates — the so-called “good” fats, like omega-3 and omega-6 fatty acids — to function properly. Studies have shown that a deficiency in the right kind of fats can actually lead to weight gain and a host of other health problems, from depression and diabetes to heart disease and inflammatory diseases such as arthritis. In addition, many of the low-fat foods we used to eat are high in calories and sugars and deprive us of the feel-full satisfaction of healthy fats. “There’s research to suggest that good fats may help to prevent you from overeating by releasing CCK [cholecystokinin],” says Toronto naturopathic doctor Penny Kendall-Reed. “CCK is the chemical messenger produced by the intestines that tells the brain when your stomach is full. That’s why people who are on low-fat diets and foraging for rice cakes still feel hungry.”
Of course, not all fats are created equal. Artery-clogging saturated and trans fats found in commercially fried foods, pastries and some dairy and meat products have minimal health benefits and go directly into fat storage. But good fats are essential to weight management: they discourage fat storage and encourage fat burning. One such proven weight-loss fat is conjugated linoleic acid (CLA), a polyunsaturated omega-6 found in grass-fed (not grain-fed or soybean-fed) beef and lamb and in safflower oils and supplements derived from safflower. Ongoing studies support the claim that CLA increases metabolic rate, preserving lean muscle tissue and reducing fat, particularly around the abdomen.
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Learn about good fats on the next page …
But another surprising recommendation that falls under this category is coconut oil. “Even though it’s a saturated fat, which is traditionally considered a ‘bad’ fat, coconut oil has been proven to boost the body’s metabolism and aid in weight loss,” says Lilian Presti, a Toronto nutritionist. The body converts lauric acid, the medium-chain fatty acid abundant in coconut oil, to energy more rapidly than it converts polyunsaturated fats, says Nina Planck, author of Real Food: What to Eat and Why. “And because of this quick conversion, little strain is put on the body’s digestive mechanisms, which speeds up the metabolism.” But if you use a saturated fat, like coconut oil, does that mean you have to choose between weight loss and heart health? According to Kendall-Reed, there’s a good side and a bad side to all oils: “If you take pure omega-3 or omega-6, for example, and heat it, it turns into a trans fat!”
But not everyone in the scientific community is convinced by the latest claims about fat. Rozwadowski doesn’t believe, for example, that changing the type of fat we eat will shrink existing fat cells. “Fat cells only shrink when our fat stores are required to supply energy to the body. In other words, you can only lose body fat by taking in fewer total calories than you expend.” Rather, Rozwadowski believes that the most important benefits of good fats lie in the reduction of inflammatory diseases and some cancers.
Where the experts do agree is on the amount of fat that Canadians should have in their diet: 25 percent, says Health Canada, with good fats comprising the bulk of this. These recommendations are now on a par with the Mediterranean diet, which includes 30 millilitres of unsaturated oils a day. If that’s not possible, then Kendall-Reed suggests taking a daily fish-oil supplement (2,000 to 3,000 milligrams of omega-3 fatty acid) with your meals. “We need to focus on getting more omega-3 in our diet,” says Rozwadowski. “Try to include fresh fish and nuts. Above all, make the enjoyment of eating a priority again.”
Our advice on choosing the right foods on the next page …
Weigh in: ELLE answers your burning fat questions
1. Whole or skim milk?
The saturated, or “bad,” fats in whole milk help your body to better absorb calcium and vitamins A and D, says Planck. But if weight loss is your goal, says Rozwadowski, opt for a lower milk-fat percentage, like skim or 1%.
2. Ice cream or yogourt?
Yogourt is the better choice in terms of its saturated and total fat content, according to Rozwadowski. Choose one with a milk-fat content between zero and 2%.
3. Olive oil or butter?
“Any liquid oil is better than a hard fat,” says Rozwadowski, because butter and margarine are high in saturated fats. Olive oil is full of vitamin E and antioxidants, adds Planck, who suggests looking for the cold-pressed varieties to get the most nutritional benefit.
4. Hard or soft cheese?
“Most cheeses are high in saturated fats,” says Rozwadowski, “but low-fat cheese tastes like rubber, so the right choice would be to enjoy the cheese you like but in moderation.” One 50-gram serving should satisfy.
5. Almonds or cashews?
“All nuts are high in good fats,” says Rozwadowski, “but they’re also highly caloric.” She recommends enjoying a small fistful of unsalted nuts each day for their healthy fat content and beneficial nutrients, including vitamin E, selenium and magnesium.