Do you burn more calories if you eat a lot in the morning and less in the evening? No, according to Scottish research. Still, a big breakfast can have its benefits.
A calorie is a calorie, you might say. Whether you take it in the morning or in the evening, it represents the same amount of energy. Or is it not that simple? There are also all kinds of indications that the time at which you eat your biggest meal of the day does matter. For example if you are trying to lose weight.
A new study, led by Alexandra Johnstone, professor of human appetite control at the University of Aberdeen, now concludes: no, if you eat a hearty breakfast, you don’t burn more calories than if you eat a hearty dinner. At the same time, it can still be useful to get your calories in especially in the morning. What’s up with that?
Also read:
Big breakfast, light dinner
For the study, Johnstone and her team worked with thirty subjects who were overweight but otherwise healthy. These people were not only told what to eat at what time, the researchers even supplied all their food and drink.
During the first week, all subjects were given a diet in which the calories were equally distributed over the morning, afternoon and evening. After that, half of them received a substantial breakfast, a regular lunch and a light dinner. The other half had a light breakfast, just lunch and a big dinner. This was followed by another week for everyone with the same number of calories at breakfast, lunch and dinner. Finally, the roles were reversed: the hearty breakfasters now received a substantial dinner for four weeks and vice versa.
Running the engine faster
The bottom line: it made no difference. Whether a test subject took in the lion’s share of his calories in the morning or in the evening, he or she used the same amount of energy. Everyone also lost almost the same amount, namely more than 3 kilos in four weeks. “Our research suggests that the distribution of calories throughout the day has no influence on how energy is processed by the body or weight loss,” says Johnstone.
Is that strange? “Based on previous studies, you would expect that people who mainly consume their calories during the first half of the day burn more calories than people who consume the same amount later in the day,” says Mireille Serlie, professor of internal medicine at Amsterdam UMC. and not involved in Johnstone’s investigation. “That turns out not to be the case. So you cannot make your combustion engine run faster and therefore lose more weight by adjusting the time at which you eat.”
less hunger
However, it could well be that it helps with weight loss if you consume a relatively large part of your calories in the morning. Johnstone and colleagues also found that the hearty breakfasters experienced less hunger during the day than the hearty diners.
Within this study, that difference in hunger could have little effect on the amount of weight loss. After all, in principle the subjects were supposed to eat all the food that the researchers had provided (although they did not always do so). But it’s conceivable that people who have full control over how much they eat will find it easier to stick to a diet if they opt for a big breakfast and a small dinner, rather than the opposite.
“I can imagine that in the longer term eating the most calories earlier in the day is beneficial for our eating behavior and therefore for weight loss,” Serlie says. Johnstone indicates that she now wants to investigate this phenomenon in more detail, by looking at test subjects who have the freedom to eat what they want, after their breakfast, whether or not they have a hearty meal.
Changes in the reward system
And why is it that a hearty breakfast causes less hunger than a hearty dinner? “In a similar study, we found that eating the most calories in the morning was associated with beneficial changes in the brain’s reward system,” Serlie says. “That could be an explanation for the differences found in hunger feelings.” Johnstone says he finds it plausible that the brain plays a role in this, and is looking forward to more research in this area.
Bronnen: Cell Metabolism, Cell Press via EurekAlert!