Review published in Advances in Nutrition finds a relationship between unhealthy food and beverage consumption and childhood obesity, but more research needed.

According to the World Health Organization (WHO), worldwide obesity has nearly tripled since 1975.  In particular, 39 million children under the age of five worldwide had overweight or obesity in 2020, and more than 340 million children and adolescents aged 5 to 19 had overweight or obesity in 2016.

These children are at a higher risk for asthma, sleep apnea, bone and joint problems, type 2 diabetes, and heart disease.  Moreover, children with obesity are more likely to experience bullying, social isolation, depression, and lower self-esteem.  Children with obesity are also at higher risk of becoming adults with obesity.  As adults with obesity, they will have a higher risk of many of the major causes of adult mortality, including coronary artery disease, hypertension, stroke, chronic kidney and liver disease as well as many types of cancer.

At the same time the incidence of childhood obesity is rising, around the world and across all socio-economic groups, children are consuming increasing amounts of unhealthy energy-dense, nutrient-poor food and beverages that are high in added sugars, salt, and saturated and trans fats.

Unfortunately, there is limited evidence on the relationship between unhealthy food and beverage consumption among children and the risk of childhood overweight and obesity.  In response, WHO commissioned a systematic scientific review to examine the risks associated with greater consumption of unhealthy foods and beverages compared to no or low consumption on overweight and obesity among children from birth up to the age of 10.9 years.  The results of this review, Unhealthy Food and Beverage Consumption in Children and Risk of Overweight and Obesity: A Systematic Review and Meta-analysis, were published in Advances in Nutrition, the international review journal of the American Society for Nutrition.

To begin their review, the authors conducted a search of the scientific literature to locate relevant studies published after 1971.  The authors placed no restriction on publication language.  Non-English studies were screened by native speakers with subject-specific knowledge.  The search eventually led to the identification of 60 studies reported in 71 articles.  All but one of the studies were observational studies.  The authors were unable to identify any studies that met their criteria that were conducted in low-income countries.  Moreover, they were only able to find very limited data on children under the age of two.

According to the review findings, “in children up to 10.9 years, consumption of sugar-sweetened beverages and unhealthy foods may increase BMI, percent body fat or odds of overweight/obesity.”  On the other hand, the authors noted, “consumption of artificially-sweetened beverages and 100% fruit juice may make little or no difference to BMI, percent body fat or overweight/obesity outcomes.”

Despite these conclusions, the authors noted that the evidence base was of low quality.  Moreover, it was difficult to synthesize the existing evidence due to the lack of uniformity among research methods employed by the studies. As a result, “the effect of unhealthy food and beverage consumption in infancy and childhood remains poorly understood, particularly in low- and middle-income settings where diets are rapidly changing, and where multiple forms of malnutrition co-exist.”  The authors stressed that “high-quality nutritional epidemiological studies that are designed to assess the effects of unhealthy food consumption during childhood on risk of overweight/obesity are needed to contribute to a more robust evidence base upon which to develop policy recommendations.”