A typical keto diet may include 20 to 25 percent of calories coming from protein, says Keene.
One common misconception is that this is a high-protein diet, when in reality, it’s moderate in protein. “Too much protein can be converted and broken down as sugar to be utilized as an energy source,” she says.
That said, you don’t want to go too low in protein. “You want to be able to stay in ketosis without sacrificing lean body mass [muscle] if you lose weight,” says Whitmire.
This can loosely equate to 1.2 to 1.5 g of protein per kilogram of body weight. (The recommended daily allowance is currently 0.8 g per kg of body weight, according to Harvard Health Publishing, so under keto it’s significantly more.)
Therefore, a 140-lb woman may aim for 76 to 95 g per day. For reference, one 3.5-ounce skinless chicken breast offers 31 g of protein.
One of the best sources of protein on a keto diet is fatty fish (like salmon or mackerel), says Keene, as it offers a source of heart-healthy protein and omega-3 fatty acids. Eggs are another good choice; one large egg contains 6 g of protein and 5 g of fat.
While a keto diet may focus on fat, that doesn’t mean you have to eat bacon and sausages all day. There is room for leaner proteins, like chicken or cod; just remember to add fat (for example, roast the chicken with olive oil) to these lower-in-fat sources, she says.
Many cuts of beef are also considered lean or extra lean, as they contain 10 g or less of total fat, as well as a modest amount of saturated fat (4.5 or 2 g or less, respectively). These include eye of round roast and steak, sirloin tip side steak, top round roast and steak, bottom round roast and steak, and top sirloin steak, notes the Mayo Clinic.