The team identified two important risk factors in consumers’ ability to regulate their blood sugar: eating late at night and carrying the melatonin receptor MTNR1B. Those who carry the MTNR1B gene and eat dinner close to bedtime may struggle to control their blood sugar levels, which may increase the risk of type 2 diabetes.
“Our study results may be important in the effort towards prevention of type 2 diabetes,” said researcher Frank A.J.L. Scheer, Ph.D. “Our findings are applicable to about a third of the population in the industrialized world who consume food close to bedtime, as well as other populations who eat at night, including shift workers, or those experiencing jet lag or night eating disorders, as well as those who routinely use melatonin supplements close to food intake.”
Avoiding food close to bedtime may be beneficial
The researchers had nearly 900 participants involved in the study. The team analyzed the group's genetic make-up to see which participants carried the MTNR1B gene. The participants then took part in a two-day experiment that required them to fast for eight hours, then alternate between an early dinner and a late dinner while keeping their usual bedtime.
“In natural late eaters, we simulated early and late dinner timing by administering a glucose drink and compared effects on blood sugar control over two hours,” said researcher Richa Saxena, Ph.D. “We also examined differences between individuals who were carriers or not carriers of the genetic variant in the melatonin receptor.”
The researchers learned that eating dinner close to bedtime made it difficult for the participants to maintain their blood sugar levels. Eating late at night was associated with higher blood sugar levels but lower overall insulin levels.
Those who carried the gene for the melatonin receptor were the most affected by later dinner times. Participants who had the MTNR1B gene and also ate close to their bedtime had higher blood sugar levels than those without the gene.
While the researchers plan to do more work in this area, they hope these findings highlight to consumers that eating too close to bedtime may come with some unintended health risks.
“Genotype information for the melatonin receptor variant may further aid in developing personalized behavioral recommendations,” Dr. Saxena said. “Notably, our study does not include patients with diabetes, so additional studies are needed to examine the impact of food timing and its link with melatonin and receptor variation in patients with disabilities.”