Calorie restriction does not appear to induce bone loss in overweight adults
September 22, 2008Young adults who follow a diet that is low in calories but nutritionally sound for six months appear to lose weight and fat without significant bone loss, according to a report in the September 22 issue of Archives of Internal Medicine.
Calorie restriction is the only intervention known to decrease the rate of biological aging and increase longevity, according to background information in the article. However, it is well known that chronic energy deficiency impairs bone mineral uptake and that weight loss is associated with bone loss in obese individuals. Calorie restriction, therefore, could also lead to bone loss and fracture.
Leanne M. Redman, Ph.D., and colleagues at Pennington Biomedical Research Center, Baton Rouge, La., studied 46 healthy, overweight men and women (average age 37) who were randomly assigned to one of four groups for six months. Eleven formed the control group, assigned to eat a healthy diet; 12 were assigned to consume 25 percent fewer calories than they expended per day; 12 were assigned to create a 25 percent energy deficit through eating fewer calories and exercising five days per week; and 11 ate a low-calorie diet (890 calories per day) until they achieved 15 percent weight loss, at which time they switched to a weight maintenance plan. All diets included recommended levels of vitamins and minerals, including calcium, and contained 30 percent fat, 15 percent protein and 55 percent carbohydrates, based on American Heart Association guidelines.
After six months, average body weight was reduced by 1 percent in the control group, 10.4 percent in the calorie restriction group, 10 percent in the calorie restriction plus exercise group and 13.9 percent in the low-calorie diet group.
Bone mineral density and blood markers of bone resorption and formation (processes by which bone is broken down and regenerated on a regular basis) were measured at the beginning of the study and again after six months. "Compared with the control group, none of the groups showed any change in bone mineral density for total body or hip," the authors write. Markers of bone resorption were increased in all three intervention groups, while markers of bone formation were decreased in the calorie restriction group but were unchanged in the low-calorie diet or calorie restriction plus exercise group.
"Our data do not support the notion that extreme weight loss (more than 10 percent) over short periods (three months) has a worse prognosis on bone health than gradual weight loss achieved over six months by moderate calorie restriction with or without aerobic exercise," the authors write. "We speculate that in young individuals undergoing calorie restriction, minor adjustments in bone occur as a normal physiological adaptation to the reduced body mass. Further studies of longer duration are warranted and should include an assessment of bone architecture to ensure that bone quality is preserved with weight loss."
Source: JAMA and Archives Journals
-
Jamb and Jamc are essential proteins for the fusion of muscle cells: study
Dec 13, 2011 |
not rated yet |
0
-
Dieters should eat foods rich in protein, mostly from dairy, to protect bones during weight loss
Nov 30, 2011 |
not rated yet |
1
-
Weight-bearing exercise does not prevent increased bone turnover during weight loss
Mar 11, 2010 |
5 / 5 (1) |
2
-
Dairy foods may improve bone health during diet and exercise in overweight premenopausal women
Nov 09, 2011 |
not rated yet |
0
-
Blood vessel mapping reveals four new 'ZIP codes'
Oct 24, 2011 |
3.7 / 5 (3) |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (30) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (3) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (1) |
0
-
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011
- More from Physics Forums - Independent Research
More news stories
Researchers develop new method for creating tissue engineering scaffolds
Researchers at Northwestern University have developed a new method for creating scaffolds for tissue engineering applications, providing an alternative that is more flexible and less time-intensive than current technology.
1 hour ago |
5 / 5 (1) |
0
|
Molecular profiling reveals differences between primary and recurrent ovarian cancers
There is a need to analyze tumor specimens at the time of ovarian cancer recurrence, according to a new study published in Molecular Cancer Therapeutics. Researchers used a diagnostic technology called molecular profiling to examine ...
1 hour ago |
not rated yet |
0
|
Health experts, scientists to discuss bird flu studies
The World Health Organization said Friday it will meet next week to determine whether scientists can publish research on a bird flu virus that may be easily passed among humans.
44 minutes ago |
not rated yet |
0
C-sections linked to breathing problems in preterm infants
Research conducted at Yale School of Medicine shows that a cesarean (C-section) delivery, which was thought to be harmless, is associated with breathing problems in preterm babies who are small for gestational age.
1 hour ago |
not rated yet |
0
US issues guidelines to avoid heparin contamination
Four years after US drug-maker Baxter International's blood thinner heparin was contaminated in China, causing dozens of deaths, US regulators on Friday issued draft guidelines for safe production.
Medicine & Health / Medications
24 minutes ago |
not rated yet |
0
Hovering not hard if you're top-heavy, researchers find
Top-heavy structures are more likely to maintain their balance while hovering in the air than are those that bear a lower center of gravity, researchers at New York University's Courant Institute of Mathematical Sciences ...
Grass to gas: Researchers' genome map speeds biofuel development
Researchers at the University of Georgia have taken a major step in the ongoing effort to find sources of cleaner, renewable energy by mapping the genomes of two originator cells of Miscanthus x giganteus, a large perenn ...
Putting the squeeze on planets outside our solar system
(PhysOrg.com) -- Using high-powered lasers, scientists at Lawrence Livermore National Laboratory and collaborators discovered that molten magnesium silicate undergoes a phase change in the liquid state, abruptly ...
Review: Netflix and Hulu's new scripted originals
Within just over a week, Netflix and Hulu are both debuting their first stabs at original scripted programming.
India probes Google over 'forex transactions'
Indian authorities are probing whether online giant Google broke domestic foreign-exchange transactions rules while shifting funds abroad, the Press Trust of India reported on Friday.
Germany freezes signing of disputed Internet pact
Germany on Friday halted the signing of a controversial international accord billed as a way to beat online piracy that has sparked angry protests, saying it needed more time to consider it.