Being a pescatarian used to be thought of as a layover on the way to becoming a full vegetarian. But more and more health-conscious eaters are swapping their steaks, burgers and boneless chicken breasts for seafood. Why? It's the easiest way to eat clean, lose weight and build muscle. Just ask converts like Cam Newton, A$AP Rocky or Olivia Wilde.

Here's a comparison: A six-ounce sirloin delivers about 50 grams of protein, along with 350 to 415 calories and 16 grams of fat (six of which are saturated fat). You get the same protein gains from six ounces of yellowfin tuna, for only 221 calories and a single gram of fat.

“Defined as a vegetarian diet with the addition of fish, the pescatarian diet can be a great choice for those searching for a nutritious meal plan,” says Chrissy Carroll, a registered dietician and triathlon coach. “Plant-based foods provide numerous vitamins, minerals and phytochemicals, while the seafood supplies omega-3 fatty acids and protein.”

Not surprisingly, fish eaters are generally healthier in a myriad of ways. They have lower incidences of certain cancers and a recent study published in the journal Circulation found that those who ate two or more seafood meals per week substantially reduced the risk of heart disease, stroke, sudden cardiac death and congestive heart failure. Even your sex life could improve—since a boost in omega-3s increases your body's nitric-oxide production, which in turn, strengthens erectile function.

What's more, there's never been a better time to try the diet out. Many grocery stores in the U.S. are now rationing the amount of meat being sold due to coronavirus outbreaks in some of the nation's processing plants. Consequently, fish is plentiful and now less expensive, since so many restaurant closures have led to a big oversupply on a range of seafood.