Un-processing Obesity: Insights into the Relationship Between Processed Foods and Obesity in Parents and Young Children

Obesity is considered a modern pandemic —and it is on the rise. One of the reasons health experts give for this phenomenon is the consumption of increasingly processed foods.  But it turns out that not all age groups may experience this phenomenon equally. A new study from the Guelph Family Health Study and lead author Rahbika Ashraf in the Department of Human Health and Nutritional Sciences found an association between ultra processed food intake and markers of obesity in adults, but not their young children.  

Ultra processed foods —which include pre-packaged meals and sweetened or salty snacks— are energy dense but have poor nutritional content. Globally, the sales of these foods are on the rise, which parallels the rise in obesity.

“We already knew that diets high in ultra processed foods are associated with weight gain and obesity in adults. But there hasn’t been a lot of research looking into the potential consequences of their intake in children, who are leading consumers of ultra processed foods,” says Ashraf, a PhD student in the lab of Dr. David Ma. Ashraf and Ma are part of the Guelph Family Health Study, which aims to determine early life risk factors that may lead to obesity and other chronic diseases.

“Dietary behaviours early in life tend to persist into adulthood. That makes it important to focus on these patterns during childhood, so that we can gain insight into later disease development and potential mitigation strategies,” Ashraf says.

The researchers looked at food intake in 242 families with young children enrolled in the Guelph Family Health Study, and classified foods according to their level of processing (from unprocessed raw or “whole” foods to minimally and ultra processed foods). They then compared the amount of processed food intake to measures such as waist circumference and body weight in parents and children.

One significant finding from this study is that both parents and children are getting most of their energy (more than 40%) from ultra processed foods. That figure may even be an underestimate, since the study considered mixed dishes as simply unprocessed or processed, potentially missing some additional ultra processed meals.

“We also show that a child’s diet closely mimics their parent’s, underscoring that foods are consumed as a household and the need for family-based interventions to reduce the consumption of highly processed foods,” Ashraf explains.

Despite the similarity in diet between parents and their kids, however, there was one key difference in the accompanying body measurements. Ultra-processed food intake was positively associated with waist circumference and body weight in parents, but not their children. 

“It was initially surprising that we didn’t find the same associations in the children, but this doesn’t mean that ultra processed foods aren’t an issue for them” says Ashraf. “It might just be difficult to disentangle from normal growth.”

Interestingly, unprocessed foods made up the second largest proportion of energy intake in both parents and their children. This was a highly encouraging finding, given that unprocessed foods were found to be inversely associated with waist circumference in children.

Despite the lack of association between ultra processed foods and obesity markers in children found in the study, Ashraf says the need for early interventions remains clear.

“What you consume as a child may influence dietary patterns in adulthood. So preschool is an important age to target with family-based intervention strategies for obesity and chronic disease prevention.”

Intervention for prevention… sounds like good advice to mention!

Read the full study in Frontiers in Nutrition.

Read about other CBS Research Highlights.