Diet drinks may not fuel appetite: study
New York, February 20, 2013
Take another sip of that Diet Coke without fear that it may be spurring your appetite. Apparently, diet soda drinkers don't eat any more sugary or fatty foods than people who stick with water instead, according to a US study.
Some researchers have proposed that drinks sweetened with artificial sugar might disrupt hormones involved in hunger and satiety cures, causing people to eat more. Others hypothesized that diet beverages could boost the drinker's preference for sweet tastes, translating to more munching on high-calorie treats.
"Our study does not provide evidence to suggest that a short-term consumption of diet beverages, compared with water, increases preferences for sweet foods and beverages," wrote lead researcher Carmen Piernas in the American Journal of Clinical Nutrition.
Piernas, from the University of North Carolina at Chapel Hill Gillings School of Global Public Health, and her colleagues, looked at 318 overweight or obese adults in North Carolina, all of whom said they consumed at least 280 calories' worth of drinks each day.
One third of the participants were advised to substitute at least two daily servings of sugary beverages with water. Another third was instructed to substitute diet drinks, including Diet Coke and Diet Lipton Tea.
"Artificial sweeteners are a lot sweeter than regular sugar, on the order of 250 times sweeter, so that's where the concerns came from," said Vasanti Malik, a nutrition researcher from the Harvard School of Public Health, who was not part of the study.
After three and six months, people reported their food and beverage intake on two different days in detail. A previous publication showed that participants in both groups lost weight.
According to the new report, water and diet beverage drinkers reduced their average daily calories relative to the start of the study, from between 2,000 and 2,300 calories to 1,500 to 1,800 calories. At both time points, people in the two groups were eating a similar amount of total calories, carbohydrates, fat and sugar.
Six months in, the only differences were that members of the water group ate more fruit and vegetables, and people randomized to diet beverages ate fewer desserts, compared to their diet habits at the study's onset.
"That's sort of the opposite of what you would expect if consumption of diet soda increased the preference for sweets," Malik told Reuters health.
Some studies have suggested an increased risk of cancer tied to certain artificial sweeteners, but convincing evidence is lacking, Malik said.
In addition, a French study, which appeared in the same journal, found that Frenchwomen who drank beverages sweetened with either real or fake sugar were more likely to be diagnosed with diabetes over 14 years than those who stuck with water.
Piernas warned that everyone in her study was heavy and trying to lose weight, so the findings may not apply to normal-weight people who drink a lot of diet beverages.
"We're trying to reduce sugar-sweetened beverage intake in the population for obesity, so the next logical question is, what substitutes can be used?" Malik said.
"I think (diet drinks) can be consumed in moderation, along with other beverages - water, coconut water, sparkling water, that type of thing."
The research was partially funded by Nestle Waters USA, which provided the water used in the study. - Reuters