If you’re debating whether to add a slice of butter to your bagel this morning, go right ahead—it’s probably a better choice for your body than low-fat spreads.
The real thing you should be worried about is the bagel.
That’s the takeaway of recent research that is upending four decades of conventional wisdom on the dangers of saturated fat, which spawned a multi-billion-dollar industry in low-fat food products touted as “healthy choices.”
Confused? You’re not alone. “The first studies were indeed surprising to us,” said Dr. Ronald M. Krauss, a director at the Children’s Hospital Oakland Research Institute.
His groundbreaking research found patients with low-fat, high-carbohydrate diets didn’t experience a reduction in heart disease. But patients eating higher levels of saturated fat, found in dairy and unprocessed meat, and lower levels of carbohydrates, such as potato chips, refined sugar and pizza, were less likely to suffer heart attacks.
“What many people, including myself, thought was accepted wasn’t holding up to more rigorous research,” Dr. Krauss says. “We decided the long-accepted relationship between heart disease and saturated fat needed to be looked at.”
Is this just another health finding that will be upended years later? “There’s been this ricocheting back and forth between extremes,” Dr. Krauss acknowledges. “It’s sort of like this binary thing: If something is true, then something else is false. Unfortunately, the picture with food is more complicated and nuanced than that.”
This doesn’t mean we should be starting our day with two scoops of lard with a side of bacon—moderation still matters. Nor does it give permission to people with health risks like high cholesterol to start piling on the red meat, Dr. Krauss adds.
Instead, the research suggests the vilification of saturated fat has been a dangerous distraction from the real foes in the battle for our waistlines and hearts: processed meats and carbohydrates, refined grains and starches, and lack of exercise.
Here are some surprising facts on saturated fat:
Dietary fat doesn’t make people ‘fat’
Fat doesn’t make us fat—sugar does. Saturated fat adds to our caloric intake, but ultimately, our digestion breaks down food into the simple sugar glucose, which provides energy to our body tissue. This sugar triggers the release of insulin, a hormone that cries “Dinnertime!” to a body’s cells and turns unused energy into fat.
“It makes sense that we would think fat would make us fat,” says Sally Kuzemchak, a dietitian who writes the Real Mom Nutrition blog. “And it has more calories—9 per gram—than carbs or sugars. But during the fat-free craze we just replaced [saturated fat] with too many starchy carbohydrates,” like that bagel you’re tucking into or other foods high in refined white flour or sugar.
Saturated fat helps make you feel full
You can’t walk down a grocery aisle without seeing packaged foods trumpeting the “low-fat,” “nonfat,” “fat-free” or “reduced fat” treats inside. The great irony is that the proliferation of low-fat food has helped American waistlines expand, researchers say. Why? If you take foods with saturated fat out of the diet, your body will hunger for a replacement—and often find it in starchy, processed carbohydrates.
“The important issue is that when reducing saturated fat, there’s an increase in intake of carbohydrates; when you make a change in one, you automatically make a change in the other,” Dr. Krauss says. “There are actually adverse results in substituting carbohydrates for fat.”
Protein-rich foods like red meat and nuts, which also contain saturated fats, are best at making the stomach feel full; snack foods rich in carbohydrates and salt often leave us wanting more. “That’s why you can eat a bag of pretzels and not feel full, even though you’ve consumed hundreds of calories,” adds Kuzemchak, author of the recent “Cooking Light Dinnertime Survival Guide.”
Not all fats are created equal
Different types of fat produce different types of cholesterol, with both good and ill effects. The ratio of “good” cholesterol (high-density lipoproteins, or HDL) to “bad” cholesterol (low-density lipoproteins, or LDL) in the bloodstream has a knock-on effect for cardiovascular health risks.
Manmade trans fats found in partially hydrogenated oils like shortening are definitely bad for the body. Fats found in olive oil and fish are rich in “good” cholesterol. The recent research moves saturated fat from the “bad” to the “neutral” column, as it contains both good and bad elements that appear to cancel one another out, Dr. Krauss says.
Steak is better for you than low-fat hot dogs
Processed meats like bologna and bacon are worse for the body than a steak. Research shows that low-fat hot dogs and processed deli meat may have less saturated fat than a steak, but as much as four times more sodium—which increases the risks of heart disease and diabetes.
Whole foods, be they beef, grains or vegetables, are always a better option than packaged foods. “Try to minimize intake of processed foods, especially processed carbohydrates,” Dr. Krauss says.
While steak may be healthier than you realized, a diet heavy on vegetables is always best, he adds. And carbohydrates such as bread or rice made from whole grains rather than refined white flour like white bread and bagels are much better for you, experts say.
Beef isn’t bad, but nuts are better
Want to know the easiest, most cost-effective way to improve your eating habits? Add two servings of nuts to your weekly diet, and you’ll cut your risk of death due to heart disease by 11 percent.
That was the conclusion of research by Dariush Mozaffarian, formerly a leading Harvard researcher and now dean of the nutrition school at Tufts University, and Simon Capewell of the University of Liverpool. The next best option, according to their research: replacing refined grains and starches with a serving of whole grains every day to reduce risk of heart-related illness by 10 percent.
“Limiting saturated fat doesn’t make the cut, because we don’t think that on its own it offers much benefit,” Mozaffarian said in a 2012 interview explaining the findings.
So put down that bagel, and pick up a handful of nuts. And feel free to butter that whole-wheat bread.
Kevin Voigt writes for NerdWallet Health, a website that empowers consumers to find high quality, affordable health care and reduce their medical bills.