If you still think that coffee is bad for you—that it’ll hurt your heart, give you diabetes, and beat up your grandma—it’s time to update your thinking.

Yes, many scientists in the 1970s and 1980s feared that coffee could cause health problems, but that was before the research community came to a deeper, richer understanding about antioxidants—compounds that can prevent or delay cell damage.

Brewed black coffee is chock full of antioxidants, and its studied benefits go far beyond disease prevention. Coffee may enhance awareness, prevent kidney stones, improve memory, turbocharge your workout, boost your mood, and even block gum inflammation and thereby decrease your risk of tooth loss.

But can coffee actually help you lose weight, as a new(ish) diet proposes that it can?

Here’s whether or not the Coffee Diet actually lives up to the buzz.

What is this whole Coffee Diet thing anyway?

It’s actually not all that complicated. Or, at least that what Bob Arnot, M.D., says in his 2017 book, The Coffee Lover’s Diet (now known as The Coffee Lover’s Bible).

Arnot, a doctor of internal medicine, has also published several other diet books, including The Aztec Diet and The Breast Cancer Prevention Diet, and (of course) has had his own line of Dr. Danger Coffee.

As Arnot details in his book, drinking at least three cups of coffee a day will, yes, prevent disease, but also help you burn fat. This amount of coffee will “boost your metabolism and cardiovascular function, while spurring weight loss,” and the research bears this out, he writes.

Well, that and a calorie-restricted diet.

Arnot writes that in addition to drinking at least three cups of black coffee a day, you should cap your calories at 1,500. Ideally, those calories should come from lean proteins, unrefined grains, and plenty of fruits and vegetables.

Okay, but does the Coffee Diet actually work?

First off, when it comes to diets, “work” is a tricky word.

Maybe your friend goes on the Coffee Diet and they lose 20 pounds and they feel amazing and they won’t shut up about the plan.

But though the Coffee Diet has worked for your friend and Dr. Bob, their experiences are anecdotal. In order for a diet to “work,” scientists have to conduct double-blind placebo-controlled dietary intervention studies, which is a phrase that is almost guaranteed to put you to sleep, but it’s the only type of study science has to determine the effectiveness of a diet plan.

And, guess what? Most diets fail those dietary intervention studies or are so new that they don’t have any scientific research behind them.

Get this: A 2017 study reviewed the results of 25 weight loss programs and found that “commercial weight-loss programs frequently fail to produce modest but clinically meaningful weight loss with high rates of attrition suggesting that many consumers find dietary changes required by these programs unsustainable.”

That that’s the other big word: “unsustainable.”

Maybe your friend is on the Coffee Diet for six months and sees results. But will they be on it for a year? Five years? The rest of their life?

Drinking three cups of coffee daily isn’t a chore, but sticking to a calorie limit of 1,500? Now that’s difficult, especially considering that the USDA currently recommends double that for the average active 19 to 35-year-old male (it’s 2,800 calories for men ages 36 to 55).

What is a healthy amount of coffee to drink if I want to lose weight?

People process coffee in different ways, but Mayo Clinic recommends capping your caffeine intake at 400 milligrams daily. That’s about the same amount that’s in four cups of brewed coffee.

And while many studies do show that three cups of coffee daily offers health benefits, you’re not hurting yourself with one or two, either, unless you find that your hydration, sleep, or focus are suffering.

One big caveat worth mentioning: This is black coffee. No cream. No sugar. No double mocha latte macchiato with a whip and some mini marshmallows for good measure. And no bottled milkshakes masquerading as “coffee” either.

If coffee motivates you to get out and exercise, then it’ll help you lose weight. And if you’re drinking it black and in moderation, instead of stuffed with calories and in a jumbo cup, you’re not going to do your waistline any damage.

Just don’t expect it to be the magic bean you need to burn fat.

Paul Kita Paul is the Food and Nutrition Editor of Men's Health.