Turns out late night dinners or snacks are not good for overall health. A recent study found that eating later in the day affects biological weight in three ways—through the number of calories that we burn, our hunger levels, and the way our bodies store fat, according to Science Alert.
Previous studies have shown the association between the timing of meals and weight gain, but for this study, researchers wanted to look at the link between the two in more detail and identify the biological reasons behind it. Neuroscientist Frank Scheer, from Brigham and Women's Hospital, Boston, said in a press statement, "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."
The study involved 16 participants with a body mass index (BMI) in the overweight or obese range. They participated in two different experiments for six days, where their sleeping and eating were tightly controlled beforehand and for several weeks between each test, according to Science Alert.
In one experiment, the participants kept to a strict schedule of three meals a day and in the second experiment, the three other meals were scheduled as lunch, dinner and supper (the first around 1 PM and the last around 9 PM). Through assessment tools such as blood samples and survey questions, the researchers made several observations.
In participants who ate later, as seen in the second experiment, levels of the hormone leptin—which tells them when they are full—were lower for 24 hours, showing that they might have felt hungrier. Moreover, their calories were burned at a slower rate. The study also showed that adipose tissue gene expression—which affects how the body stores fat—increased the process that builds fat tissues and decreased the process that breaks fat down, according to Science Alert.
"We isolated these effects by controlling for confounding variables like calorie intake, physical activity, sleep, and light exposure, but in real life, many of these factors may themselves be influenced by meal timing," said Scheer said in the statement.
The findings highlighted that late eating also increases waketime hunger and decreases waketime energy expenditure and core body temperature across 24 hours. All the changes combined may increase obesity risk, according to the paper published in the journal Cell Metabolism.
Hence, the study shows that eating earlier may be a simpler change for weight loss when compared to diets and intense exercise schedules.