Cutting back on caloric beverages can help people lose weight, but replacing them with water, rather than diet beverages, seems to have additional metabolic benefits, new trial data show.
Obese patients enrolled in the six-month CHOICE trial at the University of North Carolina, Chapel Hill, were twice as likely to lose 5% of their body weight, no matter if they'd been randomly assigned to a water group or a diet drink group, as opposed to a control group.
But the diet beverage drinkers consumed more carbohydrates and sugar than the water drinkers, researchers reported at the Obesity Society's annual meeting in Orlando, Florida.
"It has been unclear from previous research whether replacing sweetened beverages with diet beverages offers any benefits in terms of weight loss or health outcomes," Dr Douglas Hill, who conducts obesity research at the Children's Hospital of Philadelphia, but was not involved in either of the new studies, said.
Water still the best
"These studies confirm that, while substituting artificially sweetened beverages for sweetened beverages may be an effective short-term weight loss strategy, water is still the healthiest choice," Dr Hill said.
The CHOICE trial involved 315 obese participants. The two intervention groups were instructed to replace at least 200 kcal of caloric beverages every day with either water or diet drinks.
The study investigators, led by Dr Barry M. Popkin at UNC, made two presentations at the Orlando conference. In one, they reported that the odds for losing 5% of body weight were significantly higher in patients who cut back on caloric beverages.
At six months, they said, there was no difference in absolute weight between the two study groups – but those who drank water had a significantly greater improvement in fasting glucose and a trend toward a lower diastolic blood pressure compared to the control group.
No benefit for diet beverages
In the other presentation, Dr Popkin's group said that at three months into the trial, participants consuming diet drinks were more likely to be consuming more calories in general compared to the water drinkers.
And after six months, the diet beverage drinkers were more likely to consume non-sugar carbohydrates compared to the water group.
Diet beverage drinkers were also more likely to eat desserts, sweeteners and breads at three months, but not at six months, compared to the water drinkers.
"The diet beverages and consumption study suggests that one reason that previous research has not found a health benefit for diet beverages is that individuals who drink diet beverages also tend to consume more carbohydrates and sweet foods," Dr Hill said.
"Further research is necessary to investigate whether artificial sweeteners trigger a craving for more sugary foods."
(Reuters Health, Rob Goodier, October 2011)