New York, (IANS) Overweight middle-aged adults losing weight with a protein-rich diet are more likely to sleep better, than those who are losing weight consuming a normal quantity of proteins, say a new study.

"Most research looks at the effects of sleep on diet and weight control, and 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 from Purdue University in the US.

"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," Campbell added in a paper published in the American Journal of Clinical Nutrition.

The study analysed 44 overweight or obese participants who consumed either a normal-protein or a higher-protein weight loss diet.

The participants completed a survey to rate the quality of their sleep every month throughout the study.

The findings showed that those who consumed more protein while losing weight reported an improvement in sleep quality after three and four months of dietary intervention.

"Short sleep duration and compromised sleep quality frequently lead to metabolic and cardiovascular diseases and premature death," said study's first author Jing Zhou.

"Given the high prevalence of sleep problems it's important to know how changes to diet and lifestyle can help improve sleep," Zhou stated.

"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.