Consuming Many Calories After 5 p.m. May Be Harmful: Study

Research suggests that consuming more than 45 percent of daily calories after 5 p.m. may increase glucose levels and metabolic health risks.
Consuming Many Calories After 5 p.m. May Be Harmful: Study
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Consuming more than 45 percent of daily calories after 5 p.m. may dramatically spike blood sugar levels, potentially increasing risks of Type 2 diabetes and cardiovascular disease—regardless of a person’s weight or body composition.

According to a recent small study, the timing of meals may be just as crucial as what’s on your plate.

Meal Timing and Its Impact on Metabolism

The study, published in Nutrition & Diabetes in October, points out the critical role that meal timing plays in regulating health, particularly in relation to glucose levels.
Blood sugar levels that rise after evening meals take longer to decrease. Prolonged high blood sugar levels can increase the risk of Type 2 diabetes, cardiovascular disease, and chronic inflammation, co-study author Diana Díaz-Rizzolo, a postdoctoral researcher and professor at Universitat Oberta de Catalunya (UOC) in Spain, said in a statement.

The study moves beyond previous research that focused on late-night eating’s link to weight gain, which was attributed to worse dietary choices. Earlier studies indicated that hormones regulating hunger and satiety become altered when meals are consumed outside daytime hours.

However, the recent study suggests that it is the timing of meals that adversely affects glucose metabolism, irrespective of daily calorie intake or an individual’s weight.

The research involved 26 participants aged 50 to 70 years who were either overweight or obese and diagnosed with prediabetes or Type 2 diabetes.

Participants tracked their meals using a mobile app. They were divided into two groups: early eaters, who consumed most calories before evening, and late eaters, who consumed 45 percent or more of their calories after 5 p.m.

Despite having the same calorie intakes from similar food choices, late eaters exhibited worse glucose tolerance, regardless of whether they had been diagnosed with Type 2 diabetes.

One explanation might be that the body’s ability to metabolize glucose diminishes at night, according to Díaz-Rizzolo.

“The secretion of insulin is reduced, and our cells’ sensitivity to this hormone declines due to the circadian rhythm, which is determined by a central clock in our brain that is coordinated with the hours of daylight and night,” she said in the statement.

Given these findings, Díaz-Rizzolo advises prioritizing meals during daylight hours. She also recommends avoiding ultra-processed products, fast food, and foods high in carbohydrates, particularly during the evening.

Recommendations and Limitations

The study acknowledges its limitation; the small sample size confines the generalizability of the results.
In contrast to the new study results, a previous weight-loss study involving 23 people with obesity and prediabetes or Type 2 diabetes found no significant differences in weight or metabolism when comparing the effects of consuming 50 percent of total daily calories in the morning with the effects of consuming 50 percent in the evening.
George Citroner
George Citroner
Author
George Citroner reports on health and medicine, covering topics that include cancer, infectious diseases, and neurodegenerative conditions. He was awarded the Media Orthopaedic Reporting Excellence (MORE) award in 2020 for a story on osteoporosis risk in men.