Calorie restriction is an effective obesity treatment. But the results of a recent weight loss study suggest that clinicians should proceed with caution when implementing such programs for postmenopausal women, especially those with osteopenia or osteoporosis.

Australian researchers followed 101 postmenopausal women with obesity in a 12-month weight-loss trial. Participants who underwent severe calorie restriction in a meal replacement diet lost more weight and fat than did their moderately restricted peers. But they also lost approximately 1.5 times as much whole-body lean mass (proportional to total weight lost), and approximately 2.5 times as much total hip bone mineral density.

There was no difference between the two groups in whole-body lean mass or handgrip strength, the researchers added.

The trial should not discourage the use of total meal replacement diets as a treatment for obesity in postmenopausal women, wrote Radhika V. Seimon, Ph.D., University of Sydney, and colleagues. But further investigation is needed to understand the potential long-term consequences on health outcomes such as osteoporotic fractures, they concluded.

The study was published in JAMA Network Open.