Maintain or increase protein intake
When cutting calories, 9.9 times out of 10, none of them should come from protein. “Protein is the nutritional stimulus for building muscle,” Campbell says. “During a diet, it serves as the nutritional stimulus for maintaining muscle. Protein is also the most satiating nutrient—itmakes you feel full longer—and it is the least likely nutrient to be stored as fat even when eaten in excess. All of these things [make protein] a dieter’s best friend.”
For example, in one study of men who were both cutting calories and exercising, those who followed a high-protein diet lost 10.56 pounds of fat and gained 2.64 pounds of muscle. Meanwhile, those who followed low-protein diet with the same number of total calories lost 7.7 pounds of fat and gained less than a quarter pound of muscle.
How much protein you need per day depends on multiple factors, but a 2018 review concluded that, for optimal muscle growth, people should consume between 0.4 to 0.55 grams of protein per kilogram of their body weight at every meal.
“Providing a dose of 30 to 40 grams of protein every three to four hours would very rarely be a negative across the board,” adds Chad Kerksick, director of the exercise and performance nutrition laboratory at Lindenwood University in St. Charles, Missouri.