New Research: Water vs Diet Beverages for Weight Loss?

Research published in the June issue of Obesity has Twitter abuzz….for good reason! Researchers at the University of Colorado Denver compared two groups of dieters: both groups completed a 12-week behavioral weight loss program, but one group was instructed to drink at least 24 fl oz of diet beverages per day, and the other was instructed to drink at least 24 fl oz of water per day. Both groups lost weight – but after 12 weeks the diet beverage group had lost about 13 lbs, and the water group had lost about 9 lbs. Both groups did well! But alas…the diet beverage group did significantly better than the water group. Is it a bummer for those of us promoting increased water consumption as a weight loss strategy?

I don’t view it that way…water continues to be an excellent, widely accessible, and almost-free  beverage option, for those trying to cut back on calories.  But some people just don’t like water – and for them, if drinking a modest amount of diet drinks helps them stay on track with their diet plan, it is another good option.

Do these findings conflict with our water weight loss study, published in Obesity in 2010 (lead author: Dr. Liz Dennis)? I don’t think so – we used water as a pre-meal “appetizer”, 16 fl oz, three times per day…so our water “approach” was a bit different, and our water volume was quite a bit larger. We also focused on middle-aged and older adults, not the wider age range studied by the Colorado researchers. True-their age range is more generalizable to the US adult population than ours. Our focus on older adults, though, was based upon some of our earlier findings – that the pre-meal water regimen worked particularly well for the older adult population as a way to reduce meal calorie intake. We also compared our water group to a “non-water” group – who were not given any instructions about water consumption. We found that our water group lost about 5 lbs more than our non-water group – but again, both groups did pretty well and lost weight over the 12-week study period.

It seems that those trying to cut back on calories have two good beverages options – water, and diet beverages. Artificial sweeteners have stirred up quite a bit of controversy, so these findings provide solid evidence that they really can be used as part of a weight loss diet, and help people reduce their calorie intake.

For details, the 2014 study abstract can be accessed here:

http://onlinelibrary.wiley.com/enhanced/doi/10.1002/oby.20737/