Review confirms link between sugary drinks and obesity

A new review and analysis of recent studies argues that regular consumption of sugar-sweetened drinks leads to obesity and overweight in both children and adults. The authors call for stricter national policies worldwide.

According to data from the Centers for Disease Control and Prevention (CDC), 36.5 percent of all adults and around 17 percent of all children and adolescents in the United States have obesity.

A healthful diet and regular exercise are both at the core of obesity prevention and treatment.

But all too often, stores will tempt us with foods and beverages that are made to taste good, a lot of which are packed with ingredients that can exacerbate weight gain.

Sugary drinks have frequently been cited as a seemingly innocuous, easily available product with a harmful potential when it comes to preserving our health. A study published last year, for example, showed that the consumption of sugar-sweetened beverages (SSBs) is linked to the onset of metabolic diseases.

And now, researchers from multiple institutions across the globe — including the Special Institute for Preventive Cardiology and Nutrition in Salzburg, Austria, the Geneva University Hospitals in Switzerland, and the University of Navarra in Spain — have teamed up to analyze recent studies targeting the potential link between sugary drinks and obesity.

"The evidence base linking SSBs with obesity and overweight in children and adults has grown substantially in the past 3 years," says review co-author Dr. Nathalie Farpour-Lambert. "We were able to include 30 new studies not sponsored by the industry in this review, an average of 10 per year."

"[R]ecent evidence suggests that SSB consumption is positively associated with obesity in children. By combining the already published evidence with this new research, we conclude [that] public health policies should aim to reduce the consumption of SSBs and encourage healthy alternatives such as water."

Dr. Nathalie Farpour-Lambert

The review was published last week in the journal Obesity Facts, of the European Association for the Study of Obesity.

The link between sugary drinks and obesity

The researchers looked at 20 studies addressing the link between SSBs and obesity in children (17 prospective and three randomized controlled trials) as well as 10 studies investigating this link in the case of adults (nine prospective and one randomized controlled trial).

Of all the studies, 93 percent concluded that there was a "positive association" between the onset of overweight or obesity and the consumption of sugary drinks in both children and adults.

Just one prospective cohort study found no link between SSBs and excess weight in the case of children.

The review also looked at the effectiveness of interventional behavior — replacing SSBs with water and providing education counselling to the consumers — in reversing the effect of sugary drink consumption.

Among adults in the prospective cohort studies, it was found that this intervention was somewhat effective but not statistically significant. The randomized control trial, on the other hand, did not reveal any effect.

Achieving international standards

The studies included in the review involved 244,651 participants and addressed populations from Europe (33 percent of the studies), the U.S. (23 percent), Middle and South America (17 percent), Australia (7 percent), and South Africa, Iran, Thailand, and Japan (10 percent).

Review co-author Dr. Maira Bes-Rastrollo expresses her concern at the fact that sugary drinks seem to be a favorite beverage across countries and continents, placing the global population at an increased risk of obesity and other weight-related problems.

"Numerous countries across the world have high levels of SSB consumption, and even those with low intakes are observing sharp increases," she says.

"Therefore," Dr. Bes-Rastrollo goes on, "the combined evidence published before and after 2013 confirming that SSBs have adverse effects on body weight gain or obesity in children and adults provides a rationale for urgent policy action."

Dr. Bes-Rastrollo and colleagues suggest that the implementation of higher taxes on sugary drinks could curb their popularity among consumers, as well as help to diminish the risk of excessive weight gain.

So far, this strategy seems to have succeeded in Mexico, where total sales for sugary drinks have fallen by 12 percent. Some other countries also aim to introduce higher taxes for SSBs in order to discourage their consumption, following recent World Health Organization (WHO) guidelines.

"The balance between the responsibility of individuals, health advocates, and governments and society must be clarified," says Dr. Farpour-Lambert.

"It is important," she adds, "to mobilize multiple stakeholders and to develop operational synergies across different sectors. Professional networks and the food and beverages industry must be encouraged to promote healthy diets in accordance with international standards."