Kefir drink leads to a similar weight loss, compared with milk, in a dairy-rich non-energy-restricted diet in overweight or obese premenopausal women: a randomized controlled trial

Controversy exists regarding whether increasing dairy intake without energy restriction would lead to weight loss. We aimed to compare the potential weight-reducing effects of kefir drink (a probiotic dairy product) and milk in a dairy-rich non-energy-restricted diet in overweight or obese premenopausal women. One hundred and forty-four subjects were assessed for eligibility in this single-center, multi-arm, parallel-group, randomized controlled trial. Of these, seventy-five eligible women aged 25-45 years were randomly assigned to three groups, labeled as control, milk, and kefir, to receive an outpatient dietary regimen for 8 weeks. Subjects in the control group received a diet providing a maintenance level of energy intake, containing 2 servings/day of low-fat dairy products, while those in the milk and kefir groups received a weight maintenance diet, containing 2 additional servings/day (a total of 4 servings/day) of dairy products from low-fat milk or commercial kefir drink, respectively. Anthropometric outcomes including weight, body mass index (BMI), and waist circumference (WC) were measured every 2 weeks. Fifty-eight subjects completed the study. Using analysis of covariance models in the intention-to-treat population (n = 75), we found that at 8 weeks, subjects in the kefir and milk groups had significantly greater reductions in weight, BMI, and WC compared to those in the control group (all p < 0.01). However, no such significant differences were found between the kefir and milk groups. Kefir drink leads to a similar weight loss, compared with milk, in a dairy-rich non-energy-restricted diet in overweight or obese premenopausal women. However, further studies are warranted.