What You Need to Know About Popular "Fatty" Foods

While nutritionists have long praised the good fat in avocados, olive oil, and nuts, they've universally recommended avoiding food high in its stepsister, saturated fat. Because saturated fat can raise levels of bad cholesterol (LDL), it's been thought to increase your risk of heart disease. Yet while some studies supported this association, the findings were far from conclusive—and may not have taken into account other dietary factors (like the potentially negative effect refined carbs can have on the heart) or the fact that saturated fat can actually raise good cholesterol (HDL).

Still, the idea stuck: Sat fat is bad fat. But now emerging research is shedding new light on the debate. A scientific review of studies involving more than 600,000 people, published in the Annals of Internal Medicine earlier this year, found no significant link between dietary saturated fat and heart disease—suggesting that we don't, in fact, need to shun foods like red meat, butter, and whole milk for our heart's sake. But before you go hog-wild, here's what you should know about popular fatty foods.

There's a difference between unprocessed meat—like beef, lamb and pork—and the processed varieties that include sausage, bacon and lunch meat.After analyzing 20 studies, Harvard researchers found that while eating one 3.5-ounce serving or more of red meat daily wasn't associated with a higher risk of heart disease, consuming just 1.8 ounces of processed meat (the equivalent of about two slices of bologna) a day was associated with a 42 percent increased risk. The main culprit might not be the saturated fat after all, but rather the high amounts of sodium (which can raise blood pressure) and preservatives (which may promote arterial hardening) in processed meat.

Eat Smart: Sticking to one to two servings of red meat per week shouldn't have a major impact on your health if you eat well the rest of the time, says Dariush Mozaffarian, MD, an associate professor at the Harvard School of Public Health and coauthor of the Annals of Internal Medicine study. But he recommends consuming most of your protein from sources proved to be beneficial, like nuts and fish rich in unsaturated fatty acids.

While full-fat milk contains 66 more calories and four more grams of saturated fat per cup than nonfat milk, skim might not mean slim. A study of more than 19,000 middle-aged women found that consuming one serving or more of whole milk a day appeared to protect against weight gain over the course of about nine years, while drinking low-fat milk had no effect. "The extra fat in whole milk is satiating, and it's possible that we may get fuller on less," says Mario Kratz, PhD, a nutritional scientist at the University of Washington.

Eat Smart: Portions still matter, so drink no more than three cups of whole milk per day (the total recommended daily dairy intake). And consider going organic; one study found it can contain a heart-healthier mix of fatty acids, including omega-3s.

Butter and lard (pork fat) are back in favor as natural, minimally processed sources of fat (as opposed to, say, margarine). Lard is actually lower in saturated fat than butter and contains double the amount of heart-healthy monounsaturated fatty acids.

Eat Smart: Still consume these spreads in small serving sizes (a couple of teaspoons over steamed broccoli, for example) and within a healthy, whole-food-based diet.

Could Gouda be good for you? A 2012 study looked at total dairy consumption in eight European countries and found that on average, people who ate about two ounces or more cheese daily had a 12 percent lower risk of developing diabetes compared with those who consumed it sparingly. One hypothesis is that when cheese is fermented, it produces good bacteria that may help reduce cholesterol.

Eat Smart: Cheese often keeps very unhealthy company, like fast food burgers and takeout pizza, so aim to include it alongside healthier fare. And keep in mind that not all cheese is created equal: Swiss is naturally low in sodium, and Parmesan is high in protein, while feta and blue cheese are so big in flavor that a little can go a long way.