Adults eating a high-protein diet are more likely sleep better, as well as to lose weight.

"Most research looks at the effects of sleep on diet and weight control, but our research flipped that question to ask what are the effects of weight loss and diet - specifically the amount of protein - on sleep," said Wayne Campbell, a professor of nutrition science at Purdue University. "We found that while consuming a lower calorie diet with a higher amount of protein, sleep quality improves for middle-age adults. This sleep quality is better compared to those who lost the same amount of weight while consuming a normal amount of protein." These findings were published in the American Journal of Clinical Nutrition, which is affiliated with the American Society for Nutrition. The sources of protein used in the study varied from beef, pork, soy, legumes and milk protein.

"Short sleep duration and compromised sleep quality frequently lead to metabolic and cardiovascular diseases and premature death," said Jing Zhou, a doctoral student in nutrition science and the study's first author. "This research adds sleep quality to the growing list of positive outcomes of higher-protein intake while losing weight, and those other outcomes include promoting body fat loss, retention of lean body mass and improvements in blood pressure," Campbell said. "Sleep is recognised as a very important modifier of a person's health, and our research is the first to address the question of how a sustained dietary pattern influences sleep."