Testing the impact of stress on a child’s obesity risk

During the COVID-19 pandemic, we have witnessed the impact of obesity on health and mortality. Obesity triples the risk for hospitalizations and increases the risk of death. We are also seeing increases in obesity rates due to increased stress levels.

We know children are not immune to the stress and trauma experienced during the pandemic. Recent research conducted by Dr. Jeffrey Liew and his colleagues, including Marisol Perez at Arizona State University, shows some children may be more vulnerable or reactive to stress and anxiety and be at a higher risk for stress-induced eating and obesity.

“Our research findings suggest that emotion regulation and distraction strategies that are often taught through Social Emotional Learning programs may help children be resilient and better cope with stress and trauma and reduce emotional eating as well as overweight or obesity,” said Liew, professor and associate dean for research.

Liew and the research team conducted lab assessments and questionnaires assessing children four to six years old. Lab measurements focused on the child’s reactive temperament, stress-induced emotional eating and percent body fat.

“Specifically, we genotyped serotonin transporter polymorphisms 5-HTTLPR. The serotonin transporter gene has been linked to negative emotional reactivity, including anxiety-related traits, as well as impulsivity,” said Liew. “Therefore, we also assessed two reactive temperament traits in children, negative affectivity and impulsivity, by asking parents to provide information on their children using validated questionnaires.”

To test emotional or stress-induced eating, researchers asked the children to do a difficult puzzle under time pressure. They were then given sweet snacks and left alone in a room. The research team observed how many snacks they ate to determine their stress-induced reactions.

There are two types of genetic sequences associated with the serotonin transporter 5-HTTLPR, long (L) and short (S). The short sequence is associated with anxiety and negative affectivity.

“We expected that children with the S variant of the serotonin transporter gene and also had temperament traits of negative affectivity or impulsivity would be at highest risk for emotional or stress-induced eating as well as for overweight or obesity,” said Liew. “Our results showed that while children with the SL variant showed more stable rates of emotional or stress-induced eating and percent body fat, children with both the LL variant and the temperament trait of negative affectivity actually exhibited the most stress-induced eating. Furthermore, children with the SS variant were lowest on percent body fat as well as on rate and amount of stress-induced eating.” 

While parents are able to find out which variant their children carry, Liew said that piece of data in itself will not provide sufficient information to determine if their child is at risk or vulnerable to engage in emotional or stress-induced eating. Liew said the findings highlight that genetics alone cannot explain these complex behaviors.

“Across all genotypes, the higher the level of the child’s impulsivity, the faster and the more the child ate in response to stress,” said Liew. “In other words, regardless of genetics, children with the temperament trait of impulsivity are at highest risk for emotional or stress-induced eating.”

Findings from this research can help others understand the association between specific genotypes, temperament factors and emotional eating to help develop prevention or intervention for children who may be at risk for obesity.

“Pediatric obesity is a serious public health concern with long-term impacts. Children who are predisposed to overweight and obesity are at risk for becoming obese as adults,” said Liew. “Obesity is a common but serious chronic disease that puts people at risk for many other serious health issues and disease, including mobility problems, sleep and breathing problems, hypertension, and heart disease.”