A study conducted by researchers from the Open University of Catalonia in Spain showed that eating more than 45% of calories after five in the evening changes glucose levels (blood sugar), and causes serious consequences for health, regardless of the individual’s weight and body fat percentage. The new study provides the scientific basis for the common belief among people that eating a light and early dinner is better for health.
The study, published in the journal Nutrition and Diabetes, was conducted at Columbia University Irving Medical Center in New York in the United States, and was supervised by Dr. Diana Diaz Rizzolo, a postdoctoral researcher and faculty member at the Faculty of Health Sciences at the Open University of Catalonia.
Diaz-Rizzolo said – according to the Eurek Alert website -: “Maintaining high glucose levels for long periods of time can have effects that include a higher risk of developing type 2 diabetes, and an increased risk of cardiovascular disease due to the damage caused by glucose levels.” “Elevated blood vessel function and increased chronic inflammation, which exacerbates cardiovascular and metabolic damage.”
Scientists previously believed that the main consequence of eating dinner late in the day was weight gain. This was linked to the fact that people tended to make worse food choices at night, such as consuming more ultra-processed foods. The importance of the study lies in the fact that it shows that the time of day at which meals are eaten can in itself have a negative effect on the way the body processes glucose, regardless of the amount of calories consumed throughout the day and the individual’s weight and body fat.
Eating late versus eating early
The study included 26 participants between the ages of 50 and 70 who were overweight or obese, and had type 2 diabetes or pre-diabetes. The participants’ glucose tolerance levels were compared. Glucose tolerance is a test done to determine the body’s ability to use and store glucose.
The patients were divided into two groups: early eaters, who consumed most of their daily calories before the evening, and late eaters, who consumed 45% or more of their calories after 5 p.m. Both groups consumed the same amount of calories and the same foods during the day, but at different times. Participants used an app on their phones to record the actual time of their meals.
The main finding of the study is that late eaters have poorer glucose tolerance and therefore are not processed appropriately, regardless of their weight or the composition of their diet. The study also found that they tend to eat larger amounts of carbohydrates and fats during the evening.
Diaz-Rizzolo explained: “The body’s ability to deal with glucose is limited at night, because insulin secretion decreases, and the sensitivity of our cells to this hormone decreases due to the circadian rhythm, which is determined by a central clock in our brain that works in coordination with the hours of the day and night.”
The importance of eating at the right time
So the study has an important finding in terms of its effects on health and the time of day that people eat their meals. “Until now, personal decisions in nutrition have been based on two main questions: how much we eat, and what foods we choose,” Diaz-Rizzolo said. “With this study, a new factor in heart and metabolic health is starting to become more important: when we eat.”