A new study conducted on mice suggests that a low-calorie diet combined with regular physical activity could weaken bones. However, further research is required to confirm the findings.
Hitting the gym and following a balanced diet is often a way to counter summer excesses. And whether the goal is to shed a few extra pounds or to get back into shape, some of us will declare war on fats and carbs.
American researchers from the University of North Carolina are sounding the alarm against cutting out too many calories, according to a study published in the Journal of Bone and Mineral Research.
Human daily calorie requirements fall between 1,700 and 3,200 calories, depending on age, gender, and level of daily physical activity.
The study used mice to study the quantity of fat in their bone marrow. The rodents were divided into four groups: the first on a regular diet, the second on a calorie-restricted one, a third group on a normal diet with physical activity, and a fourth group on a restricted diet, which was given daily physical activity
Reduced bone density in physically-active mice
Pr. Styner's team observed that the mice from the first group lost weight while the levels of fat in their bone marrow increased, but that mice in the fourth group saw their overall bone marrow fat level decreased along with the global quality of bones. The study's authors have deduced that instead of strengthening the bones, working out could make them more fragile when combined with caloric restrictions.
"Past studies in mice have shown us that exercise paired with a normal calorie diet, and even a high calorie diet, is good for bone health. Now we're learning this isn't true for exercise along with a calorie-restricted diet," associate professor of medicine at the UNC School of Medicine, Maya Styner, MD, who is the senior author of the study
Styner and her team will be conducting further research seeking to understand the purpose of bone marrow fat its relation to diet and exercise.