(Press-News.org) In a recent study, restricting dietary fat led to body fat loss at a rate 68 percent higher than cutting the same number of carbohydrate calories when adults with obesity ate strictly controlled diets. Carb restriction lowered production of the fat-regulating hormone insulin and increased fat burning as expected, whereas fat restriction had no observed changes in insulin production or fat burning. The research was conducted at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. Results were published August 13 in Cell Metabolism.
"Compared to the reduced-fat diet, the reduced-carb diet was particularly effective at lowering insulin secretion and increasing fat burning, resulting in significant body fat loss," said Kevin Hall, Ph.D., NIDDK senior investigator and lead study author. "But interestingly, study participants lost even more body fat during the fat-restricted diet, as it resulted in a greater imbalance between the fat eaten and fat burned. These findings counter the theory that body fat loss necessarily requires decreasing insulin, thereby increasing the release of stored fat from fat tissue and increasing the amount of fat burned by the body."
The researchers studied 19 non-diabetic men and women with obesity in the Metabolic Clinical Research Unit at the NIH Clinical Center in Bethesda, Maryland. Participants stayed in the unit 24 hours per day for two extended visits, eating the same food and doing the same activities. For the first five days of each visit they ate a baseline balanced diet. Then for six days, they were fed diets containing 30 percent fewer calories, achieved by cutting either only total carbs or total fat from the baseline diet, while eating the same amount of protein. They switched diets during the second visit.
The researchers had previously simulated the study with a math model of human metabolism, whose body fat predictions matched the data later collected in the study. When simulating what might happen over longer periods, the model predicted relatively small differences in body fat loss with widely varying ratios of carbs to fat. Those results suggest the body may eventually minimize differences in body fat loss when diets have the same number of calories. More research is needed to assess the physiological effects of fat and carb reduction in the long term.
"This NIH study provides invaluable evidence on how different types of calories affect metabolism and body composition," said NIDDK Director Griffin P. Rodgers, M.D. "The more we learn about the complicated topic of weight loss, the better we can find ways to help people manage their health."
More than two-thirds of American adults are overweight or obese. Maintaining a healthy weight can help prevent complications related to overweight and obesity such as heart disease, type 2 diabetes and certain types of cancer, some of the leading causes of preventable death.
"Our data tell us that when it comes to body fat loss, not all diet calories are exactly equal," Hall said. "But the real world is more complicated than a research lab, and if you have obesity and want to lose weight, it may be more important to consider which type of diet you'll be most likely to stick to over time."
INFORMATION:
The NIDDK, a component of the NIH, conducts and supports research on diabetes and other endocrine and metabolic diseases; digestive diseases, nutrition and obesity; and kidney, urologic and hematologic diseases. Spanning the full spectrum of medicine and afflicting people of all ages and ethnic groups, these diseases encompass some of the most common, severe and disabling conditions affecting Americans. For more information about the NIDDK and its programs, see http://www.niddk.nih.gov.
About the National Institutes of Health: The NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.
Engineers from the University of Sheffield have developed a novel technique to predict when bearings inside wind turbines will fail which could make wind energy cheaper.
The method, published in the journal Proceedings of the Royal Society A and developed by Mechanical Engineering research student Wenqu Chen, uses ultrasonic waves to measure the load transmitted through a ball bearing in a wind turbine. The stress on wind turbine is recorded and then engineers can forecast its remaining service life.
When a bearing is subject to a load, its thickness is reduced by ...
Black-footed ferrets, a critically endangered species native to North America, have renewed hope for future survival thanks to successful efforts by a coalition of conservationists, including scientists at Lincoln Park Zoo, to reproduce genetically important offspring using frozen semen from a ferret who has been dead for approximately 20 years. The sire, "Scarface," as he is affectionately called by the team, was one of the last 18 black-footed ferrets to exist in the world in the 1980s. Eight kits, including offspring of Scarface, were born recently, significantly increasing ...
One of the more heartbreaking realities of Alzheimer's is the moment when a loved one struggling with the disease no longer fully recognizes a family member or close friend who is caring for them.
Now, new research from Washington University in St. Louis has identified a novel learning and memory brain network that processes incoming information based on whether it's something we've experienced previously or is deemed to be altogether new and unknown, helping us recognize, for instance, whether the face before us is that of a familiar friend or a complete stranger.
Forthcoming ...
Multigene testing of women negative for BRCA1 and BRCA2 found some of them harbored other harmful genetic mutations, most commonly moderate-risk breast and ovarian cancer genes and Lynch syndrome genes, which increase ovarian cancer risk, according to an article published online by JAMA Oncology.
Multigene panel genetic tests are increasingly recommended for patients evaluated for a predisposition to hereditary breast/ovarian cancer (HBOC). However, the rapid introduction of these tests has raised concerns because many of the tested genes are low- to moderate-risk genes ...
A study by researchers at three academic medical centers has shown that screening women with a suspected risk of hereditary breast or ovarian cancer for risk-associated genes other than BRCA1 and 2 provides information that can change clinical recommendations for patients and their family members. The report from a team led by a Massachusetts General Hospital (MGH) Cancer Center investigator is being published in the August issue of JAMA Oncology.
"The traditional approach has been to test most women with suspected hereditary risk for breast and/or ovarian cancer for ...
A University of Manchester study which followed up 38,415 people admitted to hospital with self-harm has, for the first time, investigated the association between the treatment patients receive in hospital and their subsequent risk of death.
Published in the Lancet Psychiatry, the study looked at adults who had self-harmed and attended five hospital emergency departments in Manchester, Oxford and Derby between 2000 and 2010. The researchers found that within 12 months, 261 had died by suicide and a further 832 had died from other causes.
The study also examined the ...
Organ transplant recipients are twice as likely to develop melanoma as people who do not undergo a transplant, and three times more likely to die of the dangerous skin cancer, suggests new research led by a Johns Hopkins Bloomberg School of Public Health student.
The findings, reported Aug. 13 in the Journal of Investigative Dermatology, suggest that the immunosuppressive medications that transplant recipients receive to keep them from rejecting their new organs -- especially the high doses administered at the time of transplant -- may make them more susceptible to later ...
A study on granting local sales people pricing discretion shows that profits improve by up to 11% when local sales forces are empowered to negotiate with customers. However a centralized system that uses optimization techniques and limits local sales discretion improves profits still further, by an additional 20%. The research appears in the current issue of Management Science, a publication of the Institute for Operations Research and the Management Sciences (INFORMS), the leading professional association in analytics and operations research.
"This hybrid approach balances ...
Summary: Children born with the major congenital heart defect hypoplastic left heart syndrome (HLHS) often must undergo a series of corrective surgeries beginning at birth. While most have the standard three-stage Norwood procedure, a hybrid strategy has been introduced to offset some disadvantages associated with the Norwood surgeries. In a report in The Journal of Thoracic and Cardiovascular Surgery, investigators compare whether outcomes can be improved if an arterial shunt is used as a source of pulmonary blood flow rather than the more conventional venous shunt as ...
For smokers, the number of cigarettes smoked per day and current body mass index are predictive of changes in weight after quitting smoking, according to researchers at Penn State College of Medicine.
Quitting smoking may lead to some weight gain but how much weight gain depends on the individual. Previous research shows that for some it can be just a few pounds, but for others it can be more than 25 pounds. Unfortunately, factors that can help predict the amount of weight a smoker may gain are not well understood.
"Many smokers are concerned about gaining weight after ...
