Diet drinks alone can't bear US obesity burden, and may even worsen it...

Sara Belich et al. from the John Hopkins Bloomberg School of Public Health suggest that diet drinks may lead consumers to not only make up the shortfall with solid food but also to increase overall calorie consumption.

“Overweight and obese adults drinks more diet beverages than healthy weight adults, and consume significantly more solid food calories and comparable total calories than overweight and obese adults who drink sugar-sweetened beverages (SSBs),”​ Belich et al. write.

“Heavier US adults who drink diet beverages will need to reduce solid food calorie consumption to lose weight,”​ the academics add.

Diet drinks may trick the brain’s ‘sweet sensors’​

Introducing their study, the authors cite previous papers (Dennis, Flack & Davy 2009) hypothesizing that diet sodas may alter the ‘reward’ detected by the brain’s sweet sensors, meaning that these may no longer provide an accurate gauge of energy consumption, thus encouraging higher overall food intake.

Belich et al. examined national patterns in US adult diet beverage consumption and caloric intake by body weight status using data from 23,965 participants aged 20+, taken from the nationally representative National Health and Nutrition Examination Survey (1999-2010).

Subjects filled in 24-hour dietary recalls, and the results show that 11% of healthy weight adults drank diet beverages, while the corresponding numbers for overweight and obese adults were 19% and 22%.

“Although overweight and obese adults who drink diet beverages 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,”​ Belich et al. write.

Diet drinks alone can’t carry the load​

Drinking diet products, overweight adults consumed 1,965 kcal/day on average versus 1,874 kcal for those drinking SSBs; the respective obese adult figures were 2,058 kcal and 1,897 kcal.

Discussing their results, Belich et al. note that replacing sugary drinks with diet alternatives is often recommended to those looking to lose or maintain weight, and say US adults “are heeding this advice and are using diet beverages as a means of weight control”.​

“With heavier adults increasingly switching to diet beverages, the focus on reducing SSBs may be insufficient for long term weight loss efforts,”​ Bleich et al. warn.

More research is needed to understand the impact of diet drinks on total caloric intake and obesity risk, the authors add, while more physiological studies should probe the body’s reaction to artificial sweeteners.

Responding to the study, the American Beverage Association (ABA) said in a statement: “Diet beverages have been shown to be an effective tool as part of an overall weight management plan.  Numerous studies have repeatedly demonstrated the benefits of diet beverages – as well as low-calorie sweeteners, which are in thousands of foods and beverages – in helping to reduce calorie intake. ​

"Losing or maintaining weight comes down to balancing the total calories consumed with those burned through physical activity,"​ the association added.

(Photo in text: Dawn Huczek/Flickr)

Title: ​‘Diet Beverage Consumption and Caloric Intake Among US Adults, Overall and by Body Weight’

Authors: ​Bleich, S., Wolfson, J.A., Vine, S., Wang, C.

Source: ​Research and Practice, American Journal of Public Health​, March 2014, Vol. 104, No.3. doi: 10.2105/AJPH.2013.301556​