When it comes to weight loss, it’s important to consider not only what you eat but also when you should eat. The timing of your meals may make a difference not only in the progress of your weight loss but also in your feelings of hunger and satiation, which can really make an impact on your health journey.
In this article, we take a look at the differences between eating earlier in the day compared to eating later and how it challenges the notion that “a calorie is a calorie” despite what time of the day or night it’s consumed.
Eating Early vs. Eating Later
To determine the differences between eating earlier in the day and eating later in the day, a recent study was conducted in 2022. This study examined the impact of daily calorie distribution on energy expenditure, metabolism and appetite. 30 Participants (16 male and 14 female) who were overweight and/or obese but otherwise healthy, were involved. They were randomly split into two groups, with the first group of 14 individuals subjected to the morning-loaded (ML) diet first with the remaining 16 to the evening-loaded (EL) diet. ML had their largest meal of the day at breakfast with a smaller evening meal compared to the EL diet which was a smaller breakfast meal and a large evening one.
The study showed that while there was no greater weight loss recorded from the morning-loaded diet compared to the evening-loaded diet during the trial, the ML calorie intake showed a lower appetite and desire to eat, which over time, can then aid in weight loss.
This is further reinforced in this 2019 study which aimed to narrow down on how exactly earlier eating times affected weight loss. It consisted of eleven adults who practiced an early time-restricted feeding in which they ate from 8 am to 2pm as well as a controlled eating schedule from 8 am to 8 pm. The participants followed each eating pattern for 4 days each.
The results of the early time-restricted feeding showed that the participant’s energy expenditure did not change. They did not use more calories throughout the day than normal. However, it did decrease grehlin, the hunger hormone, levels. This resulted in increased fullness and reduced appetite.
The Effects of Eating Late
It’s not just eating earlier in the day that has an impact on the body. Eating later can also have an impact, albeit in a less-than-positive way.
A 2020 study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism examined how a late dinner can impact metabolism during sleep in healthy individuals. The study consisted of 20 healthy volunteers (10 male and 10 female) between the ages of 18-30.
Each volunteer visited the clinic on two occasions, 3 to 4 weeks apart. One visit was a routine dinner, meaning that they were given an earlier dinner at 6 pm and a snack at 10 pm. The other visit switched these two meals around with a snack given at 6 pm and dinner at 10 pm. They were subjected to a fixed sleep period between 11 pm-7 am in a laboratory setting. Both times, the food and macronutrient composition remained exactly the same. These volunteers had slept in the laboratory the night prior in order to acclimatise to their setting. On the day of the trial, their breakfast and lunch were also controlled.
The results showed that a late dinner can slow down fatty acid oxidation, the process in which your body breaks down and uses fatty acids for energy.
Over time, this can lead to obesity. It’s also important to note that these effects were worsened in individuals who were accustomed to sleeping earlier and had a lesser effect on night owls.
Final Thoughts
These studies have shown that timed calorie distribution throughout the day can have an effect on weight loss. It has an impact on metabolism, the fatty oxidation process as well as feelings of hunger and satiation, which can lead to less food consumed and hence, fewer total calories.