Validity questioned of study alleging diet beverages do not prevent kids from consuming more calories

02 May 2019 --- The role of diet beverages in weight management has long stirred controversy, and a new George Washington University, US, study suggests that their consumption by children and teens may lead to a higher overall intake of sugar and calories. However, industry experts have hit back at the findings, blasting the authors’ conclusions as “inappropriate.” The report is published in Pediatric Obesity.

The study found that US children and teens consuming low-calorie or zero-calorie sweetened beverages took in about 200 extra calories on a given day compared to those who drank water. They also took in about the same number of calories as those who consumed sugary beverages. The researchers highlight the importance of their findings due to the rising rates of obesity among US children and underscore that water should be the optimal beverage choice. 

The researchers emphasize that the study was not designed to show that drinking low or zero-calorie beverages causes unhealthy weight gain. Rather, the study findings suggest a link between consuming sweetened beverages (containing sugar and/or low-calorie sweeteners) and higher intakes of both calories and sugar.

In response, the Calorie Control Council (CCC) recommends careful interpretation of the findings and has branded the conclusions of the study “inappropriate,” citing the fact that the study did not take into account two key factors: changes in body weight and overall calorie intake over time.

The researchers highlight the importance of their findings due to the rising rates of obesity among US children and underscore that water should be the optimal beverage choice. “This study reflects caloric intake over one single 24 hour period. To exert that this represents a person’s overall dietary pattern is a gross extrapolation. Additionally, the study did not examine body weight fluctuations over time. Thus, it is not able to accurately make any comments on the use of low-calorie sweetened beverages in weight management. While water is the recommended beverage of choice, consumption of LCSB remains a valid means for weight control,” says Keri Peterson, MD, Medical Advisor for the CCC.

The CCC notes that the observational nature of the study means a causal relationship between increased calorie intake and low-calorie sweetened beverages consumption cannot be proven. Also, the experts note that this study did not review the diet quality or any of the other foods consumed by the population groups over time and that its reliance on self-reported data assessed via in-person dietary recall with participants, aged 2-17, is subject to misreporting.

Despite the potential study drawbacks, however, the American Heart Association (AHA) science advisory group recently advised, “against prolonged consumption of low-calorie sweetened beverages by children.”

Diving into the study
The researchers looked at dietary recalls collected from 7,026 children and teens enrolled in the National Health and Nutrition Examination Survey from 2011 until 2016. Kids and teens reported what they ate and drank during 24 hours. The research team zeroed in on the reported consumption of sweetened beverages – those with low-calorie sweeteners and those with sugar.

Children and teens who reported drinking low-calorie sweetened beverages, such as a diet soda, not only ingested extra calories compared to water consumers, but they also took in more calories from added sugars in foods and beverages compared to water consumers, the team found.

Consumers of low-calorie sweetened drinks, sugary beverages and consumers of both took in 15, 39 and 46 extra calories from added sugar compared to water consumers. However, no differences in calorie intake were observed between consumers of low-calorie sweetened beverages and sugary beverages. The highest calorie intakes were reported in children and teens that consumed both low-calorie sweetened beverages and sugary beverages.

Is there a role for diet soda?
As noted, the use of diet beverages in weight management programs can be quite controversial. When transitioning from drinking soda to water, for example, diet beverages could play a useful role. However, concerns remain about their potential negative impacts, such as on cardiovascular health. 

Generally, children consume too much sugar, and even low-sugar beverages will contribute to these levels. Public Health England (PHE) has flagged the sugar levels present in UK children’s diets as worrying, finding that by the age of ten, children have already exceeded the maximum recommended sugar intake for an 18-year-old. The figures coincided with the launch of the Change4Life campaign from PHE in January, which encourages families to “make a swap when you next shop” in a bid to cut sugar consumption and renew focus on sugar reduction as a method to tackle childhood obesity. 

The UK has also famously instated a sugar tax on beverages with added sugars since April 2018, which pushed manufacturers to formulate lower-sugar alternatives. However, high levels of sugar remain in other popular products. 

The AHA published a science advisory that found there was inadequate scientific research to conclude whether low-calorie sweetened beverages alter risk factors for heart disease and stroke in young children, teens or adults. The AHA recognizes diet drinks may help replace high calorie, sugary beverages, but recommends water (plain, carbonated and unsweetened flavored) as the best choice for a no-calorie drink – especially for children. 

By Laxmi Haigh