If you want to lose fat [1] while building or maintaining muscle mass [2], you'll need to do more than cut calories. Eating enough protein is key [3], because protein — or more specifically, a type of protein called amino acids — serves as the building block of muscle, Torey Armul [4], MS, RD, LD, a spokesperson for the Academy of Nutrition and Dietetics, told POPSUGAR.

Still, you probably don't need as much protein as you think. "Women who want to build muscle and lose weight should aim for 0.5 to 0.8 grams of protein per pound of body weight per day," Torey said. It's important to stay in this range because too much protein can lead to weight gain [5]. So, let's say you weigh 145 pounds — you'd need between 72 and 116 grams of protein per day.

To make sure you're hitting that goal, reach for healthy, whole foods rather than supplements. "Real food contains quality proteins and other important nutrients (like vitamins, minerals, and fiber) that also keep muscles healthy and help control your weight," Torey explained. The best sources of protein [6] are foods like nuts, beans, and eggs. Dairy, poultry, fish, and legumes are also solid options for packing in your protein, but remember that you don't have to rely on meat or animal-based products to meet your quota. "Most of us are eating enough protein, but fewer are eating enough plant-based proteins [7], which play a major role in weight management and heart health," she said.

Remember too that protein alone won't help you build more muscle or lose fat. To accomplish this, you also need to work out regularly and make strength training an essential part of your routine [8]. "By working your muscles and eating protein to rebuild them you can then add to and maintain muscle mass," Torey said.