2.5/5 experts say yes*.
Americans eat almost 23 sticks of butter a year, so let's be clear that none of us is suffering from acute butter deficiency. While few health experts would encourage that you eat more of it, the question of whether butter really is back—as many magazines, including this one, has said—has many experts disagreeing.
There was a time when butter would have been a clear-cut no. After all, it’s a block of fat made of churned milk (and sometimes salt), and most of it is saturated. Just one tablespoon of salted butter, which isn't even enough to grease a grilled cheese, has 102 calories and 36% of the daily limit for saturated fat, if you are going by the Food and Drug Administration's recommendations. For many years, official U.S. dietary guidelines vilified fat—especially saturated fat—as a key contributor to excess weight cardiovascular disease.
But recent research suggests that butter—or, rather, the saturated fat it contains—might be more benign than previously thought, says investigative journalist Nina Teicholz, author of the 2014 book The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet. "For saturated fat causing heart disease, the science has never been very strong," she says. "That basically means you should let those foods that people have been avoiding for so long out of jail." Saturated fat increases levels of LDL cholesterol, which are associated with higher rates of heart disease—but saturated fat also seems to raise HDL cholesterol, which might help ease those effects.
It's safe in moderation and is a natural source of added fat, agrees Julia Zumpano, a dietitian at Cleveland Clinic’s Heart & Vascular Institute. She adds that it's a much better choice than buttery spreads that contain hydrogenated or partially hydrogenated oils.
But Dr. David Katz, director of the Yale University Prevention Research Center, avoids butter—opting instead for olive oil, which is high in monounsaturated fats and proven to improve health. The recent research indicates that, "at best, some saturated fat is 'not harmful'—there is no evidence indicating it is beneficial,” Katz says.
When thinking about butter's place in a diet, Dr. Walter Willett imagines a spectrum ranging from super healthy (blueberries) to toxic (like a 20-oz Coke, he says). "I would put butter close to the middle, maybe a little closer to the Coke," says Willett, chair of the department of nutrition at the Harvard School of Public Health.
“Thumb neutral,” concurs Dr. Dariush Mozaffarian, dean of the School of Nutrition Science and Policy at Tufts University (this represents the half-thumb* mentioned above). “No evidence it’s good for you, little evidence for major harm.”