Research suggests that keeping protein to around 1.2-1.6 grams per kilogram of body weight allows individuals to maintain or gain lean mass. Even among individuals in a calorie-restricted state, studies have found fat loss to be as high as 95 percent of total weight lost on a ketogenic diet, and consuming a ketogenic diet at maintenance calories leads to increases in muscle mass. The positive effects on muscle mass are due in part to the protein sparing and anabolic effects of ketones.
