Canadian Study Links ‘Clock Genes’ to Childhood Obesity Risk

Variations in circadian "clock genes" are linked to eating habits in young children, potentially influencing obesity risk later in life, a new study has found. Marina Demidiuk/Shutterstock

So-called “clock genes” could play a role in the risk of childhood obesity, underscoring a growing body of evidence linking sleep patterns and eating habits, a new study suggests.

Clock genes represent a category of genes that are linked to circadian rhythms, which govern cellular processes on a 24-hour timetable, according to a recent study from Guelph University that was published in the journal Nutrients in June.

Although all humans share the same genes, individual variations in these genes account for traits like hair and eye colour, the researchers said. For this study, they examined variations in circadian rhythm-related genes that were associated with differences in eating habits, including higher calorie intake and changes in specific macronutrient intake in young children, it found.

The findings contribute to a growing body of evidence linking circadian genetics to dietary behaviour, Guelph University human health sciences professor Dr. David Ma said in a press release.

“Clock genes have garnered substantial interest as modulators of disease risk,” Ma said. “These findings show that listening to the natural rhythms of our bodies is important, which can influence eating behaviour and chronic disease risk later in life. This matters because healthy behaviours such as sleep, physical activity, and eating behaviours are learned early in life.” 

Earlier studies have identified associations between circadian genetics and dietary habits, the researchers said, but this is the first study to investigate the relationship between clock genes and dietary habits in preschool-aged children.

Researchers analyzed dietary records from 168 children between the ages of two and six, focusing on eight clock genes associated with obesity, diabetes, and dietary behaviours. This developmental stage is crucial because early dietary habits can influence the risk of diseases later in life, said Guelph Family Health Study bioinformatician Zach Ribau.

The researchers said dietary habits during the early stages of childhood growth may influence the risk of developing diseases later in life.

“In this paper, we looked at just one point in time,” Ribau said in the press release, but noted that additional observational studies are underway, which may allow for more detailed hypotheses to be uncovered.

The researchers involved in the project are also investigating family behaviours, nutrition, sleep and stress, and will look at how these affect the long-term health of young children while offering strategies for healthy habits.  

He said they will look at whether the associations hold up as the children and parents grow older.

“This research is in its infancy,” Ribau said. “It is a complex picture. In no way would this be the only thing to consider, but it is a factor for obesity in children.”