The global study covered data from 185 countries over 18 years: finding an alarming increase in children's intake of sugar from soda and other soft drinks.
Measures which specifically target marketing of SSBs to children and adolescents have now become ‘critical’, warn the researchers behind the study.
Why are children drinking more sugar?
Why has sugary drink consumption among children shot up? Explanations include the globalization of markets, which give soda brands wider reach and make sugary-drinks more accessible to children around the globe.
There's also the transformation of food systems, which also result in wider availability of unhealthy foods.
Another factor is an increase in 'aggressive marketing strategies' directed at children and adolescents, suggest the researchers behind the BMJ study.
And - a point they emphasize most strongly - there's been a lack of regulatory measures to limit sales of sugary beverages to children.
Led by Laura Lara-Castor of Tufts University in Boston, the international team of researchers from the US, Mexico, Canada and Greece used data from the Global Dietary Database, which incorporated more than 1,200 national and subnational dietary surveys from 185 countries (450 surveys from 118 countries included specific data on SSB intake).
Data were analysed for children and adolescents aged 3-19 years in 185 countries between 1990 and 2018.
SSBs were defined as any drink with added sugars and at least 209 kJ (50 kcal) per 237g serving.
That included soft drinks, energy drinks, fruit drinks, punch and lemonade, but excluded 100% fruit and vegetable juices, non-caloric artificially sweetened drinks, and sweetened milk.
The results show that intakes of SSBs among children and adolescents increased by an average of 23% (0.68 servings/week) from 1990 to 2018.
But this picture changes enormously by region.
In 2018, the average global intake was 3.6 standard servings per week. That ranges from 1.3 servings in south Asia to 9.1 servings in Latin America and the Caribbean.
Yet 56 (30%) of the 185 countries included in the analysis - home to 238 million children and adolescents or 10.4% of the global population of young people - had an average SSB intake of 7 or more servings/week.
The largest increases were seen in sub-Saharan Africa (2.17 servings/week).
Among the 25 most populous countries, the highest intakes of SSBs were in Mexico among 10-14 year olds (11.9 servings/week) and 15-19 year olds (12.8 servings/week).
The lowest were in Kenya and China among 3-4 year olds (0.2 servings/week each).
SSB intakes also varied according to demographics.
Globally, SSB intakes were higher in older versus younger children and adolescents, those resident in urban versus rural areas, and those of parents with higher versus lower education (with variations by world region).
There was little difference, however, between consumption among girls and boys.
Researchers acknowledge limited availability of dietary survey data in some countries, particularly for lower income nations in south Asia and sub-Saharan Africa.
The data also relies on self-reported survey data, which could be under or over reported.
But the findings ‘should be taken as the best currently available’, they say.
The high costs of sugar consumption
Backing previous research, the data presented a positive correlation between intake of SSBs and prevalence of obesity in children.
What's particularly concerning is that obesity in childhood tends to persist into adulthood: increasing the risk of type 2 diabetes, cardiovascular disease and premature mortality.
This finding needs ‘particular attention’ given the incremental economic costs associated with overweight and obesity globally, which are projected to increase from about $2.0tn (£1.6tn; €1.9tn) in 2020 to $18tn by 2060, exceeding 3% of the world’s gross domestic product.
A particular problem for Latin America and the Caribbean
Researchers found a worrying increase in SSB consumption in Latin America and the Caribbean. In 2018, the mean intake of SSBs was 9.1 servings a week, compared to the global average of 3.6 servings a week.
Latin America and the Caribbean actually experienced an overall decrease in intakes of SSBs from 1990 to 2005, which could be attributed to the economic crisis experienced among most of the major economies in the region during this period. Healthy eating campaigns also become more prevalent.
But the increases in SSB consumption in this region from 2005 to 2018 may relate to economic recovery, increased marketing campaigns, and industry opposition to public policies to reduce the intake of SSBs, suggest researchers.
From sugar taxes to school restrictions: What policies should be considered?
The findings of the study highlight the necessity for public policy interventions on SSBs, say the researchers.
So what could these look like?
Sugar taxes, regulations on front-of-package labeling, and regulations in the school environment are all methods proposed by the researchers.
"All of these policies have shown to be effective on their own, but a combination of these would likely yield more successful and sustainable effects," lead author Lara-Castor told us.
One prime example of the potential of soda taxes is the UK soft drinks industry levy, which was introduced in 2018 and taxes beverages according to their sugar content.
This was not covered by the BMJ study, which ended in 2018. But, with the UK levy having now been in place for five years, a number of other studies have looked at the impact.
For children, cereal, soft drinks, and fruit juice are the biggest contributors to free sugars. But for adults, the largest sources of free sugars are sugar, preserves, confectionery and non-alcoholic drinks.
A study from University College London, published in the BMJ in July, looked specifically at reductions in sugar intake among children compared to adults.
At the start of the study in 2008, children consumed about 70g of added sugars daily, which dropped to 45g by 2019, a 9.7% reduction compared to expected levels without the sugar tax. For adults, intake went from 60g to 45g per day, a 19.8% reduction.
Other work from UCL’s Child Health team of researchers have linked the introduction of the tax to reductions in obesity, dental caries, and asthma admissions in children.
When it comes to restrictions in schools, a number of US states have introduced such soda regulations. California, for example, was the first state to pass state level regulations as early as 2004, banning all SSBs in elementary and middle schools, and later restricting access to SSBs in high schools.
Regulations on front-of-pack labeling could take a number of different forms. One idea that's been considered by various researchers is the concept of tobacco-style warnings on pack.
A study from the University of North Carolina at Chapel Hill found that picture warnings reduced parents' purchases of sugary drinks for their kids by 17%.
A 2020 study noted a similar decline (14.5%) in consumption of sugar-sweetened drinks among students who were shown warning labels on drinks.
Meanwhile, stark tobacco-style health warnings resulted in a 43% decline in sugar-sweetened fruit drinks among Latinx parents, according to a study.
