American College of Physicians: Internal Medicine — Doctors for Adults ®

ACP EHR Partner Program
Advice, comparisons and reviews from ACP members help you select the right EHR system.

Advertisement
Advertisement
Thursday, January 5, 2012

QD: News Every Day--Body fat is all about the excess calories

Consuming excess calories increases body fat, regardless of how many calories come from protein. High-protein diets do affect energy expenditure and storage of lean body mass, just not body fat storage.

To evaluate the effects of overconsumption of low-, normal-, and high-protein diets on weight gain, researchers conducted a single-blind, randomized controlled trial of 25 healthy, weight-stable adults in an inpatient metabolic unit in Baton Rouge, La. Patients were ages 18 to 35 with a body mass index between 19 and 30. The study was headed by George A. Bray, MD, MACP.

After consuming a weight-stabilizing diet for 13 to 25 days, participants were randomized to diets containing 5% of energy from protein (low protein), 15% (normal protein) or 25% (high protein). Only the kitchen staff who supervised participants while they were eating knew the assignments. There was no prescribed exercise, and alcohol and caffeine were restricted.

Patients were overfed during the last 8 weeks of their 10- to 12-week stay with the protein diets, which provided 40% more energy intake, or 954 kcal/d.

Body composition was measured by dual-energy X-ray absorptiometry biweekly, resting energy expenditure was measured weekly by ventilated hood, and total energy expenditure by doubly labeled water prior to the overeating and weight stabilization periods and at weeks 7 to 8. Results appeared in the Jan. 4 issue of the Journal of the American Medical Association.

Overeating produced significantly less weight gain in the low-protein diet group (3.16 kg; 95% confidence interval [CI], 1.88 to 4.44 kg) compared with the normal protein diet group (6.05 kg; 95% CI, 4.84 to 7.26 kg) or the high protein diet group (6.51 kg; 95% CI, 5.23 to 7.79 kg) (P=.002). Body fat increased similarly in all three protein diet groups and represented 50% to more than 90% of the excess stored calories.

Resting energy expenditure, total energy expenditure, and body protein did not increase during overfeeding with the low-protein diet. Resting energy expenditure increased significantly with the normal and high protein diets (normal protein diet: 160 kcal/d [95% CI, 102 to 218 kcal/d]; high protein diet: 227 kcal/d [95% CI, 165 to 289 kcal/d]), as did lean body mass (normal protein diet: 2.87 kg [95% CI, 2.11 to 3.62 kg]; high protein diet: 3.18 kg [95% CI, 2.37 to 3.98 kg]).

"[C]alories are more important than protein while consuming excess amounts of energy with respect to increases in body fat," the authors wrote.

While the authors noted that low-protein diets resulted in less weight gain than normal- or high-protein groups when extra calories were eaten, the limits of a low-protein approach were evident when considering changes in body composition and energy expenditure.

With the low-protein diet, more than 90% of the extra energy was stored as fat. Because there was no change in lean body mass, a 6.6% increase in total energy expenditure reflects the energy cost of storing fat.

An accompanying editorial noted that low-protein diets are usually higher in empty calories and hidden fats, compared to protein-rich diets that encourage building lean muscle mass instead of fat.

"The results suggest that overeating low-protein diets may increase fat deposition leading to loss of lean body mass despite lesser increases in body weight," the editorial said. "Clinicians should consider assessing a patient's overall fatness rather than simply measuring body weight or body mass index and concentrate on the potential complications of excess fat accumulation. The goals for obesity treatment should involve fat reduction rather than simply weight loss, along with a better understanding of nutrition science."

Labels: , , , ,

posted by Ryan DuBosar at 7:00 AM  

0 Comments:

Post a Comment

Subscribe to Post Comments [Atom]

<< Home

Share

 

Contact ACP Internist

Send comments to ACP Internist staff at acpinternist@acponline.org.

Previous Posts

Blog log

Members of the American College of Physicians contribute posts from their own sites to ACP Internist and ACP Hospitalist. Contributors include:

Albert Fuchs, MD
Albert Fuchs, MD, FACP, graduated from the University of California, Los Angeles School of Medicine, where he also did his internal medicine training. Certified by the American Board of Internal Medicine, Dr. Fuchs spent three years as a full-time faculty member at UCLA School of Medicine before opening his private practice in Beverly Hills in 2000.

Zackary Berger
Zackary Berger, MD, ACP Member, is a primary care doctor and general internist in the Division of General Internal Medicine at Johns Hopkins. His research interests include doctor-patient communication, bioethics, and systematic reviews.

CasesBlog
Ves Dimov, MD, ACP Member, is an allergist/immunologist and Assistant Professor of Medicine and Pediatrics at the University of Chicago, where he evaluates and treats both pediatric and adult patients.

David Katz, MD
David L. Katz, MD, MPH, FACP, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care.

db's Medical Rants
Robert M. Centor, MD, FACP, contributes short essays contemplating medicine and the health care system.

DrDialogue
Juliet K. Mavromatis, MD, FACP, provides a conversation about health topics for patients and health professionals.

Dr. Mintz' Blog
Matthew Mintz, MD, FACP, has practiced internal medicine for more than a decade and is an Associate Professor of Medicine at an academic medical center on the East Coast. His time is split between teaching medical students and residents, and caring for patients.

Everything Health
Toni Brayer, MD, FACP, blogs about the rapid changes in science, medicine, health and healing in the 21st century.

FutureDocs
Vineet Arora, MD, FACP, is Associate Program Director for the Internal Medicine Residency and Assistant Dean of Scholarship & Discovery at the Pritzker School of Medicine for the University of Chicago. Her education and research focus is on resident duty hours, patient handoffs, medical professionalism, and quality of hospital care. She is also an academic hospitalist.

Glass Hospital
John H. Schumann, MD, FACP, provides transparency on the workings of medical practice and the complexities of hospital care, illuminates the emotional and cognitive aspects of caregiving and decision-making from the perspective of an active primary care physician, and offers behind-the-scenes portraits of hospital sanctums and the people who inhabit them.

Gut Check
Ryan Madanick, MD, ACP Member, is a gastroenterologist at the University of North Carolina School of Medicine, and the Program Director for the GI & Hepatology Fellowship Program. He specializes in diseases of the esophagus, with a strong interest in the diagnosis and treatment of patients who have difficult-to-manage esophageal problems such as refractory GERD, heartburn, and chest pain.

I'm dok
ACP Member Mike Aref, MD, PhD, ACP Member, is an academic hospitalist with an interest in basic and clinical science and education, with interests in noninvasive monitoring and diagnostic testing using novel bedside imaging modalities, diagnostic reasoning, medical informatics, new medical education modalities, pre-code/code management, palliative care, patient-physician communication, quality improvement, and quantitative biomedical imaging.

Informatics Professor
William Hersh, MD, FACP, Professor and Chair, Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, posts his thoughts on various topics related to biomedical and health informatics.

Just Oncology
Richard Just, MD, ACP Member, has 36 years in clinical practice of hematology and medical oncology. His blog is a joint publication with Gregg Masters, MPH.

KevinMD
Kevin Pho, MD, ACP Member, offers one of the Web's definitive sites for influential health commentary.

MD Whistleblower
Michael Kirsch, MD, FACP, addresses the joys and challenges of medical practice, including controversies in the doctor-patient relationship, medical ethics and measuring medical quality. When he's not writing, he's performing colonoscopies.

Medical Lessons
Elaine Schattner, MD, ACP Member, shares her ideas on education, ethics in medicine, health care news and culture. Her views on medicine are informed by her past experiences in caring for patients, as a researcher in cancer immunology, and as a patient who's had breast cancer.

More Musings
Rob Lamberts, MD, ACP Member, a med-peds and general practice internist, returns with "volume 2" of his personal musings about medicine, life, armadillos and Sasquatch at More Musings (of a Distractible Kind).

Musing of an Internist
Justin Penn, MD, ACP Associate Member, attended medical school at the University of Washington School of Medicine and trained in internal medicine at the University of Rochester, where he is serving as Chief Resident.

Prescriptions
David M. Sack, MD, FACP, practices general gastroenterology at a small community hospital in Connecticut. His blog is a series of musings on medicine, medical care, the health care system and medical ethics, in no particular order.

Reflections of a Grady Doctor
Kimberly Manning, MD, FACP, reflects on the personal side of being a doctor in a community hospital in Atlanta.

Technology in (Medical) Education
Neil Mehta, MBBS, MS, FACP, is interested in use of technology in education, social media and networking, practice management and evidence-based medicine tools, personal information and knowledge management.

White Coat Underground
Peter A. Lipson, MD, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. The blog, which has been around in various forms since 2007, offers musings on the intersection of science, medicine, and culture.

Other blogs of note:

American Journal of Medicine
Also known as the Green Journal, the American Journal of Medicine publishes original clinical articles of interest to physicians in internal medicine and its subspecialities, both in academia and community-based practice.

Clinical Correlations
A collaborative medical blog started by Neil Shapiro, MD, ACP Member, associate program director at New York University Medical Center's internal medicine residency program. Faculty, residents and students contribute case studies, mystery quizzes, news, commentary and more.

Interact MD
Michael Benjamin, MD, ACP member, doesn't accept industry money so he can create an independent, clinician-reviewed space on the Internet for physicians to report and comment on the medical news of the day.

PLoS Blog
The Public Library of Science's open access materials include a blog.

White Coat Rants
One of the most popular anonymous blogs written by an emergency room physician.

Powered by Blogger

RSS feed