If this is not your name, click here.
| | If this is not your name, click here. | | |
| | Contact Us | Order Now | Journals | Bookstore | Register a colleague | | |
| |  Calorie Restriction Does Not Appear to Induce Bone Loss in Overweight Adults CHICAGO -- September 22, 2008 -- Young adults who follow a diet that is low in calories but nutritionally sound for 6 months appear to lose weight and fat without significant bone loss, according to a study in the September 22 issue of Archives of Internal Medicine. Leanne M. Redman, PhD, and colleagues at Pennington Biomedical Research Center, Baton Rouge, Louisiana, studied 46 healthy, overweight men and women (mean age 37 y) who were randomly assigned to 1 of 4 groups for 6 months. The control group consisted of 11 participants assigned to eat a healthy diet. Another 12 were assigned to consume 25% fewer calories than they expended per day, 12 were assigned to create a 25% energy deficit through eating fewer calories and exercising 5 days per week, and 11 ate a low-calorie diet (890 calories per day) until they achieved 15% 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% fat, 15% protein, and 55% carbohydrates, based on American Heart Association guidelines. Bone mineral density and blood markers of bone resorption and formation were measured at the beginning of the study and again after 6 months. After 6 months, average body weight was reduced by 1% in the control group, 10.4% in the calorie restriction group, 10% in the calorie restriction plus exercise group, and 13.9% in the low-calorie diet group. "Compared with the control group, none of the groups showed any change in bone mineral density for total body or hip," the authors wrote. Markers of bone resorption were increased in all 3 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 over short periods has a worse prognosis on bone health than gradual weight loss achieved over 6 months by moderate calorie restriction with or without aerobic exercise," the authors wrote. "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: Archives of Internal Medicine
|
