Dieting Without Exercise Harms Bone Health


    Men and women who lose weight through caloric restriction, without exercise,
    also lose bone at the hip and spine, increasing their risk for the bone-thinning
    disease osteoporosis and fractures, a study shows. Adding regular exercise to a
    calorie-restricted diet helps shield the bones from the harmful effects of
    dieting.

    “Exercise protects
    against bone loss during voluntary weight loss,” Dr. Dennis T. Villareal, who
    led the study, told Reuters Health. “Therefore, it would be important to combine
    calorie restriction and exercise to derive the benefits of weight loss and
    preserve bone.”

    Villareal, from
    Washington University School of Medicine in St. Louis, and colleagues studied
    the effects of weight loss on bone loss in 30 women and 18 men whose average age
    was 57 years. The study subjects were overweight but not obese.

    For one year, 19
    subjects stuck to a calorie-restricted diet; 19 ate their usual number of
    calories but engaged in regular exercise; and 10 in a comparison “control” group
    received healthy lifestyle tips only. All but two participants completed the
    yearlong study.

    At the end of the 12
    months, the dieters lost an average of 18.1 pounds, while the exercisers lost
    14.8 pounds and those in the control group had no significant change in their
    weight.

    As reported in the
    Archives of Internal Medicine, the dieters lost an average of 2.2 percent of
    bone density in the lower spine and at the hip. In contrast, there were no
    significant changes in bone mineral density in the exercise group or healthy
    lifestyle groups.

    The action of
    muscles pulling on bones during exercise is thought to produce “healthy” strain
    on the skeleton that stimulates the production of new bone, the investigators
    note. The current study supports this line of thought.

    “It’s important that
    calorie restriction not be seen as a bad thing,” Villareal said, “because it
    offers enormous benefits with respect to reducing disease risk and is effective
    for weight loss. Also, there is a real possibility that calorie restriction
    provides anti-aging benefits that cannot be achieved through exercise
    alone.”

    However, to maintain healthy bones, “exercise should be an important
    component of a weight loss program to offset adverse effects of calorie
    restriction on bone,” the team concludes.

    Follow

    Get every new post delivered to your Inbox.

    Join 879 other followers