BALTIMORE — Losing weight can be hard, there’s no doubt about it. While poor diet and lack of exercise are often the primary culprits in weight gain, recent research shows that eating a late dinner may also be to blame.
The study, published in the Journal of Clinical Endocrinology & Metabolism, finds that people who eat a late dinner burn less fat overnight. They also have higher blood sugar levels than those who eat dinner earlier.
Previous research already demonstrates an association between late night eating and weight gain. This latest work aimed to determine whether late eating changes metabolism in a way that promotes obesity.
How time you eat dinner impacts metabolism
For their research, the authors had 20 healthy volunteers (10 men and 10 women) eat dinner at 6 p.m. or 10 p.m. All participants ate the same meal and went to bed at the same time (11 p.m.). The researchers used body fat scans, activity trackers, hourly blood samples, and non-radioactive tracers (which participants ingested through the food they ate) to examine blood sugar levels and fat burning.
Results show that fat burning is reduced by 10% and peak blood sugar levels are almost 20% higher in late dinner eaters compared to early dinner eaters. They also found that these effects are most pronounced in people who regularly go to bed earlier.
“This study sheds new light on how eating a late dinner worsens glucose tolerance and reduces the amount of fat burned. The effect of late eating varies greatly between people and depends on their usual bedtime,” says researcher Dr. Jonathan Jun, in a media release. “This shows that some people might be more vulnerable to late eating than others. If the metabolic effects we observed with a single meal keep occurring chronically, then late eating could lead to consequences such as diabetes or obesity.”
People with preexisting metabolic conditions may be particularly susceptible to the negative health effects of late eating, the authors say. “The effects we have seen in healthy volunteers might be more pronounced in people with obesity or diabetes, who already have a compromised metabolism,” adds lead author Dr. Chenjuan Gu.