The study’s revelations may provide credence as to how sleep quality can be improved. Short sleep duration and compromised sleep quality frequently lead to metabolic and cardiovascular diseases and premature death.
"Given the high prevalence of sleep problems it's important to know how changes to diet and lifestyle can help improve sleep," said Jing Zhou, a doctoral student in nutrition science and the study's first author.
Purdue University researchers enrolled 44 overweight or obese participants, who were invited to consume either a normal-protein or a higher-protein weight loss diet.
After three weeks of adapting to the diet, the groups consumed either 0.8 or 1.5 grams of protein for each kilo of body weight daily for 16 weeks. The sources of protein used in the study varied from beef, pork, soy, legumes and milk protein.
The participants completed a survey to rate the quality of their sleep every month throughout the study. Those who consumed more protein while losing weight reported an improvement in sleep quality after three and four months of dietary intervention.
More protein benefits
"This research adds sleep quality to the growing list of positive outcomes of higher-protein intake while losing weight. Other outcomes include promoting body fat loss, retention of lean body mass and improvements in blood pressure," said Dr Wayne Campbell, a professor of nutrition science at Pursue University.
"We've showed an improvement in subjective sleep quality after higher dietary protein intake during weight loss, which is intriguing and also emphasises the need for more research with objective measurements of sleep to confirm our results."
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.115.124669
“Higher-Protein Diets Improve Indexes of Sleep in Energy-Restricted Overweight and Obese Adults: Results from 2 Randomized Controlled Trials.”
Authors: Jing Zhou, Jung Eun Kim, Cheryl LH Armstrong, Ningning Chen, and Wayne W. Campbell