Everyone loves a good villain, and that holds true even for what we eat. “We always look for food scapegoats, the pariah food we shouldn’t go near,” says Leslie Bonci, RD, director of sports nutrition at the University of Pittsburgh Medical Center and co-author of Walk Your Butt Off. Establishing a verboten list simplifies the task of making healthier meal choices. But nutrition research is an ongoing process. “Scientists need time to tease out the different components in foods,” says Lona Sandon, RD, assistant professor of clinical nutrition at the University of Texas Southwestern in Dallas. Here, five foods that have gone from forbidden to favored.
Downside: Cheese contains a great deal of fat (an ounce of Gouda has about eight grams).
Upside: The fat that’s so dangerous for your thighs contains conjugated linoleic acid (CLA), a fatty acid that recent research suggests is good for your heart. In a 10-week Italian study, healthy adults who each day ate about one ounce of cheese high in CLA experienced significant improvements in markers of systemic inflammation, which is a risk factor for atherosclerosis, heart disease and strokes. One likely explanation: CLA is an anti-oxidant, which as a class helps protect against heart disease, notes Thomas Wilson, PhD, associate professor of nutritional science at the University of Massachusetts Lowell.
In addition, probably because of its anti-inflammatory effects, CLA may help lower cancer risks and prevent age-related muscle and bone loss, says Mizanur Rahman, PhD, assistant professor of clinical immunology and rheumatology at the University of Texas Health Science Center at San Antonio. The cheeses highest in CLA include blue cheese, Brie, Edam, Swiss and sharp Cheddar.
Caveat: An ounce of cheese, which is about the size of four dice, ranges from 49 calories for ricotta to 113 for Cheddar. “It’s easy to overeat cheese, and many people do,” says Christine Gerbstadt, MD, RD, an attending physician at Walter Reed Hospital in Bethesda, Maryland. Gerbstadt recommends sticking with one or two ounces a day if you’re concerned about your weight.
Downside: Long a favorite beverage among kids, chocolate milk was on the dietary no-no list for adults for many years because it contains added sugar and a lot of calories (209 per eight ounces).
Upside: “During the first minutes after exercise, your body rebuilds and repairs muscle tissue,” says Kim Spaccarotella, PhD, an exercise researcher and a lecturer at Kean University. Research done in the past five years suggests that chocolate milk aids with that post-workout recovery. The beverage contains four key ingredients—protein, carbs, fluids and electrolytes—that facilitate muscle repair when consumed within 45 to 60 minutes after a workout.
Caveat: While there’s nothing wrong with having low-fat or fat-free chocolate milk as a healthy treat now and then—it packs a hefty dose of calcium—you can easily drink too much. Unless you’re cutting out the 200 calories elsewhere or exercising long or hard, introducing chocolate milk may wreak havoc with your diet.
Downside: Ever since the low-carb craze kicked into high gear in the 1990s, white-colored foods, including potatoes, have gotten a bad rap.
Upside: Most of these foods (such as white bread, white sugar and white-flour pasta) are white because they are heavily refined, with fiber and other natural nutrients stripped away. “The difference is, white potatoes come out of the ground that color,” explains Orlando, Florida, nutritionist Tara Gidus, RD, author of The Flat Belly Cookbook for Dummies. Unprocessed potatoes are rich in an ingredient called resistant starch, a kind of carbohydrate that makes you feel full and keeps you that way longer. Resistant starch is not completely broken down by digestive enzymes, leaving it to be consumed by certain bacteria in the GI tract. “These bacteria produce by-products that in turn stimulate the production of leptin, a hormone that shuts off your appetite,” Sandon explains. A 2012 Australian study found that obesity-prone rats gained much less weight when they consumed high levels of resistant starch.
Research from Louisiana State University suggests that the hormonal changes sparked by resistant starch may be especially beneficial as we get older. The starch balances “the populations of bacteria in the intestine,” explains -Maria Marco, PhD, professor of food science and technology at the University of California Davis. “Those changes might result in improved glucose tolerance, reduced levels of systemic inflammation and better appetite control.”
Caveat: To avoid excess fat, eat white potatoes boiled or baked (not fried) and don’t slather them with butter, cheese, sour cream or bacon bits. Healthier toppings include plain Greek yogurt or a tablespoon of grated Parmesan.
Downside: Egg yolks are one of the most concentrated sources of dietary cholesterol—they contain about 184 milligrams—and people concerned about their blood levels of cholesterol have long avoided eggs or egg yolks.
Upside: The current thinking is that “the real culprits for high blood cholesterol are saturated fats, trans fats and overconsumption of processed carbohydrates,” says Bonci. In fact, eggs may even be good for the heart. A study in Atherosclerosis reported that adults referred for coronary angiography who consumed more than one egg per week had less plaque clogging their coronary arteries than their peers who ate eggs less frequently. This may be partly because eggs supply a precursor of nitric oxide, which keeps blood vessels functioning.
Recently, the benefits of eggs have earned them new respect: Eggs are rich in protein, vitamins A and D, iron and lutein (a carotenoid beneficial for the brain and eyes), and the yolk is a great source of choline, a nutrient in which many women are deficient.
Caveat: While it’s safe for many people to consume up to an egg a day, those with multiple risk factors for cardiovascular disease should check with their doctor. Some studies suggest that regular egg consumption may lead to an increased risk of heart disease among diabetics.
Downside: Its high fat content and big calorie count (two tablespoons contain 16 grams of fat and 190 calories) long ago landed it on the dietary taboo list.
Upside: In recent years, nutrition experts have recognized that peanut butter contains mainly heart-healthy monounsaturated and polyunsaturated fats rather than the artery-clogging kind. Peanut butter may also improve blood sugar regulation, which reduces the risk for type 2 diabetes. A recent study in the British Journal of Nutrition found that overweight women who ate peanut butter as part of a healthy breakfast experienced a smaller rise in blood sugar after the meal than a control group not given peanut butter. The reason: Peanut butter “reduces blood sugar jumps by slowing the body’s absorption of carbohydrates,” explains study coauthor Richard Mattes, PhD, professor of nutrition science at Purdue University. In the study, the peanut butter eaters also had less desire to eat, 120 and 370 minutes later, than the control subjects.
Caveat: Since peanut butter is so high in calories, portion control is key. That means it’s fine to spread a tablespoon or two onto a slice of whole-grain bread but not to continuously dip a spoon into the jar. Also, be sure you’re buying the natural version, which contains nothing but ground peanuts and maybe a touch of salt.
And one to Avoid...Coconut Oil: Don’t Fall for the Hype
This fat, derived from coconuts, “has taken off in the vegan and Paleo diet worlds,” says Leslie Bonci, RD, director of sports nutrition at the University of Pittsburgh Medical Center. To proponents, coconut oil is a healthier saturated fat than some others. A few components of the saturated fat in coconut oil prevent your body from absorbing all its calories. Plus, “more calories are expended in the breakdown of coconut oil than with other fats,” Bonci notes.
Yet many nutritionists aren’t sold on coconut oil. “It’s a case of the marketing getting ahead of the science,” says Lona Sandon, RD, assistant professor of clinical nutrition at the University of Texas Southwestern. Even if coconut oil is not metabolized exactly the same way as most other saturated fats, many experts won’t put it on the list of health-promoting foods. They note that there is very little (if any) research to suggest that coconut oil actually provides health benefits. It’s still a form of fat and contains 117 calories per tablespoon. You’re better off cooking with monounsaturated oils such as extra-virgin olive oil and canola oil, which are known to provide cardiovascular benefits and reduce the risk of diabetes, advises Amy Jamieson-Petonic, RD, spokesperson for the Academy of Nutrition and Dietetics.