An incredible new study released on Monday found that people who go on a low-calorie diet for weight loss are putting their bones at risk for degeneration. This new research directly contradicts the erroneous contention by many so-called health “experts” that low-carb diets are detrimental to bone health.
Lead researcher Dr. Dennis T. Villareal, Associate Professor of Medicine in the Division of Geriatrics and Nutritional Science at the Washington University School of Medicine in St. Louis, Missouri, observed 48 adults (18 males and 30 females) with an average age of 57 and an average BMI of 27 as they lost weight over a period of one year.
The study participants were split into one of three groups:
GROUP 1 (CR) – A total of 19 of them were placed on a calorie-restricted diet by reducing their calorie consumption by 16 percent in the first three months and by 20 percent for the remaining nine months of the study.
GROUP 2 (EX) – Another 19 of them were placed on the same diet as GROUP 1 except they also began a simultaneous exercise program.
GROUP 3 (HL) – The final 10 participants were given information on living a “healthy lifestyle” when they requested it. Otherwise, they were not given any specific instructions.
The study participants in each group were weighed at the beginning of the study and at the end of one month, three months, six months, nine months and one year. For the purposes of measuring bone density during the study, Dr. Villareal used a dual-energy x-ray absorptiometry once per quarter to measure the differences.
Additionally, blood samples were taken at the beginning of the study, after six months and at the end of the study to test for hormones and chemical markers that would determine whether bone tissue was being absorbed and regenerated.
All but two of the study participants were able to finish the research.
At the end of the one-year study, participants in GROUP 1 had lost an average of 18.1 pounds, GROUP 2 had lost an average of 14.8 pounds, and GROUP 3 experienced no weight loss or weight gain.
Interestingly, the bone density of the calorie-restricted GROUP 1 decreased by 2.2 percent in their lower spines, another 2.2 percent in their hips, and yet another 2.1 percent at the top of their leg. Each of these parts of the body are most susceptible to injury.
GROUP 2 and GROUP 3 did not experience any measurable difference in bone density.
The researchers found that those who exercise while losing weight do not experience the same decline in bone density because the muscles pulling on the bones during physical activity actually stimulates new bone production.
“Our results are consistent with an osteoprotective effect of exercise-induced mechanical strain on the skeleton and consequent increase in bone turnover,” the authors stated.
Dr. Villareal and his colleagues believe their research provides evidence that more effective diet and exercise methods need to be studied to help prevent the loss of bone density in at-risk patients for osteoporosis.
“These findings have important implications in designing an appropriate weight-loss therapy program in middle-aged adults, particularly in the subset of patients who may already be at increased risk for bone fracture,” they concluded.
The results of this study appear in the December 11, 2006 issue of the Archives Of Internal Medicine.
What was fascinating to me is the assumption by the researchers that the best “lifestyle modification” for weight loss is “exercise and low-calorie diets.” And yet this supposedly “healthy” diet is exactly what is leading to bone loss.
Hmmm, so what’s with all the vicious talk about low-carb diets being bad for your bones? This common myth that has been bantered around so freely for years about livin’ la vida low-carb with nary a shred of any evidence to prove it has now been turned around and placed on the other foot.
Are we going to hear about how “dangerous” low-calorie diets are for you now? How about warnings from health officials about being careful with such risky “fad” diets like low-calorie? Should we have people sue those companies that provide low-calorie foods to put warning labels on their products since people could break a bone?
Sounds silly, doesn’t it? Well, that’s exactly what critics like the National Osteoporosis Society have been doing to the low-carb lifestyle change that has helped so many people lose weight and get healthy. Even more incredible to me is the fact that low-carb has actually been proven in studies to improve bone density in the hip and heel. Have you heard about this anywhere else besides my blog? Not likely.
The fact is, as another study has shown, that low-carb bone loss is a myth perpetrated by the enemies of livin’ la vida low-carb. It’s just not true and these antagonists have known it from the beginning. Now we know the truth–it’s LOW-CALORIE diets that lead to bone loss, NOT low-carb ones! How will the spin doctors wiggle their way out of this one?
You can e-mail Dr. Dennis T. Villareal about his study at dvillare@im.wustl.edu.
12-15-06 UPDATE: Dr. Villareal responded to my blog post today stating his interest at looking into the effect of a low-carb diet on bone density health as well:
Thank you for the interest. Also thank you for the suggestion on looking at low-carb diet. There is already an ongoing study on that I think, but will certainly consider it in future studies if funding permits.
Dennis T. Villareal, MD
Associate Professor of Medicine
Division of Geriatrics and Nutritional Science
Washington University School of Medicine
We’ll be looking forward to seeing that research, Dr. Villareal! THANK YOU for your ongoing efforts to educate the public on sound nutritional choices.
