Food 'compensation' means diet drinks are not a weight loss solution, warn researchers

22-Jan-2014 - Last updated on 22-Jan-2014 at 14:11 GMT

Overweight people who drink more sugar-free and diet sodas counterbalance their lower caloric intake by consuming more sweet snacks, warn the researchers,

Overweight and obese adults who drink sugar-free or diet beverages consume more calories from food than overweight people who drink regular soda, according to new data.

The results of a large US-based study involving more than 23,000 adults has suggested that people who are overweight or obese drink more sugar-free beverages than people of a healthy weight. However, the study which examined patterns in adult diet beverage consumption and calorie intake, also found that overweight and obese adults who drink diet beverages consume more calories from food than obese or overweight adults who drink 'regular soda' or other sugar sweetened beverages (SSBs) - thus counterbalancing any reduction in calorie intake from drinking the sugar-free beverage.

"Although overweight and obese adults who drink diet soda eat a comparable amount of total calories as heavier adults who drink sugary beverages, they consume significantly more calories from solid food at both meals and snacks," explained Dr Sara Bleich an associate professor with the Bloomberg School's Department of Health Policy and Management and lead author of the paper.

Writing in the American Journal of Public Health, Bleich and her colleagues suggested that earlier research linking artificial sweeteners to greater activation of reward centres in the brain may explain why they found higher consumption of solid food among heavy adults who drink diet beverages.

Study details

The team used data 23,965 participants who took part in the 1999-2010 National Health and Nutrition Examination Survey (NHANES) to investigate national patterns in adult diet beverage consumption and caloric intake by body-weight status.

Overall the team found that 11% of healthy-weight, 19% of overweight, and 22% of obese adults drink diet beverages.

While this data supports the notion that obese and overweight people wish to monitor caloric intake and reduce their weight, the team also found that overweight and obese drinking diet beverages consumed "significantly more solid-food calories and a comparable total calories than overweight and obese adults who drink SSBs."

Bleich and her colleagues added that although total caloric intake was higher among adults consuming sugar-sweetened beverages compared with diet beverages (2351 kcal/day vs 2203 kcal/day; P = .005), this difference was only significant for healthy-weight adults (2302 kcal/day vs 2095 kcal/day; P < .001)

"Among overweight and obese adults, calories from solid-food consumption were higher among adults consuming diet beverages compared with SSBs," they said.

As a result, the team suggested that adults who drink diet beverages will need to reduce solid-food calorie consumption to lose weight.

"Overweight and obese adults looking to lose or maintain their weight - who have already made the switch from sugary to diet beverages - may need to look carefully at other components of their solid-food diet, particularly sweet snacks, to potentially identify areas for modification," Bleich added.

Source: American Journal of Public Health
Published online ahead of print, doi: 10.2105/AJPH.2013.301556
"Diet-Beverage Consumption and Caloric Intake Among US Adults, Overall and by Body Weight"
Authors: Sara N. Bleich, Julia A. Wolfson, et al