People who ate at this time were half as likely to be hungry afterwards.
Although the common advice for losing weight is avoid snacking, little research has looked at the impact of late eating on appetite and body weight regulation.
Body weight is regulated by factors such as the number of calories we burn, structural changes in fat cells, and regulation of energy intake.
A study has found that the time of eating greatly influences hunger and appetite, molecular pathways in adipose tissues, and amounts of energy that our body needs.
Professor Frank Scheer, the study’s lead author, said:
“We wanted to test the mechanisms that may explain why late eating increases obesity risk.
Previous research by us and others had shown that late eating is associated with increased obesity risk, increased body fat, and impaired weight loss success.
We wanted to understand why.”
Dr Nina Vujović, the study’s first author, said:
“In this study, we asked, ‘Does the time that we eat matter when everything else is kept consistent?
And we found that eating four hours later makes a significant difference for our hunger levels, the way we burn calories after we eat, and the way we store fat.”
Early eating vs. late eating
The study examined the outcome of early eating and late eating on 16 overweight and obese people.
Participants had to complete an early eating protocol and a late eating protocol during the in-laboratory stays.
The early eating protocol included breakfast, lunch, and dinner with a 4-hour break between each and the last meal consumed 6 hours and 40 minutes before bedtime.
Meals for the the late eating protocol were similar to the early eating protocol but subjects skipped breakfast and had lunch, dinner, and supper which was 2 hours and 30 minutes before bedtime.
During the stay participants blood samples were taken, body temperature, energy expenditure, hunger and appetite were recorded.
Samples of adipose tissue were collected to see how meal timing affects molecular pathways in fat cells and how fat is stored in the body.
This enabled the team to compare gene expression profiles between the two eating conditions and the results showed that late eating changed the lipid metabolism pathways.
They found that eating late alerted appetite-regulating hormones: ghrelin levels went up while leptin levels went down, resulting in more hunger.
Also, subjects burned less calories and had elevated levels of adipogenesis (formation of fat cells) and reduction of lipolysis (a process that fat breaks down).
These findings show a direct relation between late eating and increased risk of developing obesity.
Professor Scheer said:
“This study shows the impact of late versus early eating.
Here, we isolated these effects by controlling for confounding variables like caloric intake, physical activity, sleep, and light exposure, but in real life, many of these factors may themselves be influenced by meal timing.
In larger scale studies, where tight control of all these factors is not feasible, we must at least consider how other behavioral and environmental variables alter these biological pathways underlying obesity risk.”
The study was published in the journal Cell Metabolism (Vujović et al., 2022).
