High dairy protein intake by overweight women may aid bone formation during diet and exercise

Overweight and obese premenopausal women who increased dairy food and protein intake during weight loss regimens developed improved markers for bone formation and decreased markers for bone degradation, according to a study set for publication in the Journal of Clinical Endocrinology & Metabolism.

“Our findings show that a diet with a high proportion of dairy foods and higher than recommended protein intake was associated with improved markers for bone health,” study author Stuart Phillips, PhD, of McMaster University in Hamilton, Ontario, stated in a press release from The Endocrine Society. “Thus, to avoid deleterious consequences to their bone health, women who are attempting weight loss through dieting should practice consumption of more protein from dairy sources.”

Phillips and colleagues divided 90 study participants — premenopausal overweight or obese women — equally into three groups that had either high protein, high dairy intake (HPHD), adequate protein and medium dairy intake (APMD) or adequate protein, low dairy intake (APLD). In addition to moderate calorie restriction, trial participants in all groups performed modest daily exercise, such as aerobics and resistance training, according to the release.

At baseline, participants’ mean body mass index ranged from 27 to 40 kg/m² and mean age ranged from 19 to 45 years and they were habitually low dairy consumers, according to study data.

To draw their conclusions, investigators calculated bone mass density results using dual-energy X-ray absorptiometry scans and monitored vitamin D, dietary calcium and protein levels of patients in all three groups.

Although patients in the three groups lost the same amount of weight after 16 weeks, the findings showed the HPHD group had greater total fat loss, greater visceral fat loss and lean muscle gains. The APMD group saw similar results but at a lower rate, suggesting both diets offered adequate protection against potential bone resorption and loss.

The researchers concluded high protein intake with a focus on dairy foods during diet and exercise periods can help overweight and obese women’s markers for bone turnover, calcium, vitamin D status, and bone metabolism, according to the release.

“Our data provide a good rationale to recommend consumption of dairy foods to aid in high quality weight loss, which we define as loss of fat as opposed to muscle, and the promotion of bone health in young women who are at the age when achieving and maintaining peak bone mass is of great importance,” Phillips stated in the release.

Reference:

Josse AR, Atkinson SA, Tarnopolsky MA, Phillips SM. Diets higher in dairy foods and dietary protein support bone health during diet- and exercise-induced weight loss in overweight and obese premenopausal women [published online ahead of print November 2, 2011]. J Clin Endocrin Metab. doi:10.1210/jc.2011-2165.

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