ORLANDO, Fla. – Malnutrition in its many forms remains a world-wide epidemic. In the United States, more than 60 percent of adults are classified as overweight or obese, whereas third-world nations are struggling with under-nutrition and insufficient food supplies. A new study provides scientific insight that may benefit development of public health policy to influence healthy weight gain. A study published today in the Journal of the American Medical Association (JAMA) examines the impact of diets containing varying amounts of protein on weight gain, body composition and energy expenditure. The research, led by Steven R. Smith, M.D., Florida Hospital – Sanford-Burnham Translational Research Institute, and George Bray, M.D., Pennington Biomedical Research Center, found that total calories account for increases in body fat, while increasing the percent of dietary protein during overfeeding led to more lean body mass storage. The research appears to be the first to analyze the impact of dietary protein during overfeeding and provides guidance on dietary composition for healthy weight gain.
Consuming a high protein/low calorie diet for weight loss has been a well-known, yet controversial method of dieting. Protein in the diet may raise resting energy expenditure, effectively burning calories. The study’s investigators were intrigued by this principle and decided to look at the impact of varying levels of protein during overconsumption to better understand metabolic changes that occur during obesity. Dr. Steven Smith, scientific director of the Translational Research Institute for Metabolism and Diabetes, was the principal investigator on the research protocol and one of the first authors.
“A large number of studies have been performed to understand the role of protein to help dieters. Our work addresses the possibility that protein is important to help prevent weight gain through increased calorie burning,” explained Dr. Smith.
Participants lived in an inpatient unit for 10 to 12 weeks. Initially, test subjects consumed a weight stabilizing diet while their energy expenditure was measured. Subsequently, they were fed diets with 40 percent higher energy value with eitherfive percent (low), 15 percent (normal), or 25 percent (high) of calories from protein. Body composition was measured biweekly using a whole body scanner. Body fat increased similarly in all three protein diets. Resting energy expenditure and body protein increased significantly with the normal and high protein diets. While the low protein diet resulted in less total weight gain, all of the weight was deposited as fat. In contrast, weight gain on the mid- and high-level protein diets included increased lean body mass.
The study is remarkable for its duration and number of participants, having evaluated 25 participants for 24 hours per day during a 10-week inpatient period. The authors believe that this is the first study to analyze the impact of three levels of dietary protein during overfeeding and one of a few to calculate both resting and total energy expenditure.
“As obesity develops, metabolic changes occur that reflect the differences in the way that individuals process food. The next phase of research will evaluate the mechanisms that account for the increased energy burned,” said Dr. Smith. “Understanding how the body increases calorie burning will provide insight into novel ways to rev up metabolism as a way to treat metabolic diseases, such as obesity, diabetes, and cardiovascular diseases.
Orlando’s soon-to-open Translational Research Institute for Metabolism and Diabetes (TRI), a collaboration between Sanford-Burnham Medical Research Institute and Florida Hospital, will enable this kind of cutting-edge clinical research in metabolism. The new facility will house clinic space, testing rooms, a 3T MRI scanner, a DEXA scan, calorimetry rooms to measure energy metabolism, and a biorepository. These and other technologies will help researchers understand the metabolic origins of obesity and diabetes. The TRI is expected to open in early 2012.
This study was funded by the United States Department of Agriculture (USDA) and Louisiana State University. The primary investigator was Dr. George A. Bray of Pennington Biomedical Research Center, Baton Rouge, La. Dr. Steven R. Smith of the Translational Research Institute for Metabolism and Diabetes, Orlando, Fla., was primary investigator on the research protocol. Both Drs. Bray and Smith contributed equally to this work. Co-authors include George Bray, Pennington Biomedical Research Center; Steven R. Smith, Translational Research Institute; Lilian de Jonge, National Institutes of Health; Hui Xie, Translational Research Institute; Jennifer Rood, Pennington Biomedical Research Center; Corby K. Martin, Pennington Biomedical Research Center; Marlene Most, St. James Place; Courtney Brock, Pennington Biomedical Research Center; Susan Mancuso, Pennington Biomedical Research Center; and Leanne M. Redman, Pennington Biomedical Research Center.
About the Translational Research Institute for Metabolism and Diabetes
The Florida Hospital – Sanford-Burnham Translational Research Institute for Metabolism and Diabetes (TRI) is the product of an innovative affiliation between Florida Hospital and Sanford-Burnham Medical Research Institute at Lake Nona. By linking the largest not-for-profit hospital in the country with a nationally renowned basic science leader, the TRI bridges the gap between the research bench and the patient’s bedside. The mission of the TRI is to extend and improve the quality of lives through the translation of fundamental scientific discoveries to the diagnosis and treatment of human disease.
The TRI’s new 54,000-square-foot, technologically advanced translational research facility is currently under construction at Florida Hospital’s Health Village in Orlando and is expected to open in early 2012. For additional information, please visit http://www.tri-md.org/ .
About Sanford-Burnham Medical Research Institute
Sanford-Burnham Medical Research Institute is dedicated to discovering the fundamental molecular causes of disease and devising the innovative therapies of tomorrow. Sanford-Burnham, with operations in California and Florida, is one of the fastest-growing research institutes in the country. The Institute ranks among the top independent research institutions nationally for NIH grant funding and among the top organizations worldwide for its research impact. From 1999 – 2009, Sanford-Burnham ranked #1 worldwide among all types of organizations in the fields of biology and biochemistry for the impact of its research publications, defined by citations per publication, according to the Institute for Scientific Information. According to government statistics, Sanford-Burnham ranks #2 nationally among all organizations in capital efficiency of generating patents, defined by the number of patents issued per grant dollars awarded.
Sanford-Burnham utilizes a unique, collaborative approach to medical research and has established major research programs in cancer, neurodegeneration, diabetes, and infectious, inflammatory, and childhood diseases. The Institute is especially known for its world-class capabilities in stem cell research and drug discovery technologies. Sanford-Burnham is a nonprofit public benefit corporation.
For more information, please visit http://www.sanford-burnham.org/.
About Florida Hospital
Opened in 1908, Florida Hospital is a faith-based institution focused on providing whole person care. It is one of the largest not-for-profit hospitals in the country, caring for more than a million patient visits per year – more than any other hospital in the country, according to the American Hospital Association. The more than 2,000-bed system is comprised of eight hospitals, including the Walt Disney Pavilion at Florida Hospital for Children, 30 outpatient facilities and 20 Centra Care locations throughout Central Florida.
Florida Hospital provides a wide range of health services, including many nationally and internationally recognized programs in cardiology, cancer, women’s medicine, neurosciences, diabetes, orthopedics, pediatrics and advanced surgical programs. Florida Hospital is a designated statutory teaching hospital and also trains physicians from all around the world on the newest technologies.
For more information, please visit http://www.floridahospital.com/.