Late Night Meals Bad for Blood Sugar Control and Weight Loss

A study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism has found that eating a late may be a contributing factor to weight gain and hyperglycemia -- factors that may also exaccerbate heart disease.

The researchers studied how subjects metabolized dinner eaten at 10 p.m. compared to 6 p.m. in 20 healthy volunteers (10 men and 10 women). The volunteers all went to bed at 11 p.m. The researchers found that for the same meal,  blood sugar levels were higher, and the amount of ingested fat burned was lower if it was eaten later.

“On average, the peak glucose level after late dinner was about 18 percent higher, and the amount of fat burned overnight decreased by about 10 percent compared to eating an earlier dinner. The effects we have seen in healthy volunteers might be more pronounced in people with obesity or diabetes, who already have a compromised metabolism,” said the study’s first author Chenjuan Gu, M.D., Ph.D., of the Johns Hopkins University.

To gather the data, participants wore activity trackers, had blood sampling every hour while staying in a lab, underwent sleep studies and body fat scans, and ate food that contained non-radioactive labels so that the rate of fat burning (oxidation) could be determined.

“We still need to do more experiments to see if these effects continue over time, and if they are caused more by behavior (such as sleeping soon after a meal) or by the body’s circadian rhythms,” said the study’s corresponding author Jonathan C. Jun, M.D., of the Johns Hopkins University School of Medicine in Baltimore, M.d.

Gu C, Brereton N, Schweitzer A, et al. Metabolic Effects of Late Dinner in Healthy Volunteers - A Randomized Crossover Clinical Trial [published online ahead of print, 2020 Jun 11]. J Clin Endocrinol Metab. 2020;dgaa354. doi:10.1210/clinem/dgaa354