Eat breakfast as soon as you wake up or wait a couple of hours? This is what science says about perfect timing

For decades we have heard the incomprehensible mantra that “breakfast is the most important meal of the day”, however, nutrition has been advancing to put the focus now when we eat and not what it is eaten. But here chrononutrition studies how the timing of our food affects our metabolism; has a lot to say about it.

A schedule. If you are one of those who jump out of bed straight to the toaster or, on the contrary, one of those who need a couple of hours to pass for their stomach to “open”, you have probably asked yourself: what is the ideal time to have breakfast? And to answer this question, we have to turn to science.

The biological clock. Something very important here is that our body does not process food the same at eight in the morning than at eight in the afternoon, all because our circadian clock and insulin sensitivity fluctuate throughout the day.

According to classic reviews in this field, aligning the onset of feeding with the active phase of our circadian rhythm improves glucose homeostasis, lipid control, and thermogenesis. The bottom line here is that our body is better prepared to manage energy in the morning.

The studies. Here, a large review published in 2023 followed more than 100,000 people and its results were conclusive in pointing out that eating breakfast after 9:00 in the morning increases the risk of developing type 2 diabetes. 59% compared to doing it before 8:00.

But constantly delaying the first meal of the day and shifting caloric intake towards the evening is associated with a higher cardiovascular risk and worse metabolic markers at the population level. Therefore, the premise we have on the table right now is that eating breakfast early offers a great advantage.

But with nuances. Having breakfast early is good, but… Does it have to be as soon as you open your eyes? There is no clinical trial here that dictates that you should eat food at minute zero after waking up, and in fact, waiting a little can bring benefits metabolic under certain situations.

One of them, which came from a trial published in 2025compared people who ate breakfast early, at 8:30, with another group of people who ate breakfast mid-morning, at 10:30. Here, surprisingly, mid-morning breakfast reduced the glycemic response of the following meal to make it more efficient. This indicates that the time interval between breakfast and lunch influences how our body processes sugar hours later.

More cases. In the case of being diagnosed with type 2 diabetes, a trial observed that delaying breakfast until mid-morning or even at noon managed to reduce the blood glucose that occurred after eating.

What needs to be done. For most adults, science suggests that it is best to eat breakfast within the first hour or two of waking up, so there is no need to get out of bed and start eating because it seems to be the most efficient. But if we want to be precise, the limit may be nine in the morning, since delaying the first time we drink something too much in the day until noon and having dinner late is the perfect recipe for metabolic imbalance.

In short, there is no need to force yourself to swallow toast with your eyes still glued to sleep. Letting your body wake up, doing your morning routines, and eating breakfast an hour after waking up not only respects your natural rhythms if you’re not immediately hungry, but it has solid clinical support.

Images | freepik

In Xataka | We’ve been telling ourselves for 100 years that breakfast is the “most important meal of the day.” The problem is that it is not true