Two hour gap between dinner and sleep is overrated says Japanese research

By Dr. Ananya Mandal, MDJan 22 2019

We have been advised to take a light dinner and leave a gap of at least two hours between dinner and bed time in order to maintain a healthy body weight. Now, new research suggests that this is not really necessary. The study results appear in the latest issue of the journal BMJ Nutrition, Prevention and Health.

Image Credit: PAKULA PIOTR

Experts have had us believe that going to be right after dinner can have a long term ill effect on health and also raise the risk of diseases such as cancer. New research coming from the Graduate School of Health Sciences at Okayama University in Japan has found that this gap is not necessary to maintain a healthy blood sugar level. The Japanese are advised to leave a two-hour gap between their dinner and bed time at least thrice a week for good health. The study was conducted out by Su Su Maw (a Ph.D nursing student), and Chiyori Haga, associate professor in the Department of Nursing at Okayama University.

The team analyzed information gathered from 1,573 healthy middle aged and older adults living in Okayama in western Japan between 2012 and 2014. The population of two thirds women and most were over the age of 65 years. None of the participants were diabetic. They looked at the diet, lifestyle, smoking status and other factors of these participants. Blood glucose levels as well as HbA1c levels of these participants were monitored. Some of the participants (16 percent men and 8 percent women) went to bed regularly within two hours of their dinner.

Results showed that HbA1c levels of the cohort of participants had a steady rise from 5.2 per cent average in 2012 to 5.58 per cent in 2013 and 2014. This was seen irrespective of the time gap between dinner and bed. Researchers could conclude that the time gap had little effect on the blood glucose control of participants. On the other hand, blood glucose control was significantly affected by lack of physical activity, excessive alcohol consumption, obesity, raised blood pressure and other detrimental lifestyle habits.

The authors of the study write, “Contrary to general belief, ensuring a short interval between the last meal of the day and bedtime did not significantly affect HbA1c levels... More attention should be paid to healthy portions and food components, getting adequate sleep and avoiding smoking, alcohol consumption, and overweight, as these variables had a more profound influence on the metabolic process.”