Should we leave a gap of several hours between meals?

So far, this appears to be more of a fashion than something backed by scientific evidence. "The body regulates itself well and doesn't need to rest. No studies have confirmed that intermittent fasting is the panacea or that it can be just as healthy to eat three times a day as it is six," warns Luis A. Zamora, a dietician and founding member of the Spanish Society of Dietetics and Nutrition.

Dr Francisco Pita Gutiérrez of the Spanish Society of Endocrinology and Nutrition agrees.

"The body's metabolism is active at all times, although during periods of fasting or gaps between meals some metabolic processes predominate over others. There is no need for the body to rest, unless someone is ill. Although in general the digestive system tolerates a higher number of small meals best, there is no ideal number," he says. .

There can be, if we analyse the situation case by case, of course: "For a person who eats impulsively, it is better to have something every two or three hours so they don't get so hungry and eat the first thing in front of them," says Zamora, and he insists that it is the effect of the food on the body that basically determines what we eat:

"If I have an apple, and two hours later a couple of carrots, some pulses at midday, a banana mid-afternoon and a good evening meal, there will be no problem. Do I generate glucose spikes every time I eat? Yes, but they will be gentle spikes, like flat mountains," he says. The problem, he warns, is that "when you have a coffee and an hour later a croissant, then some chocolate, for example, the body has to 'squeeze' to produce insulin. Because it suddenly receives a lot of sugar and has to remove it from the blood, what it does is transforms it into fat and stores it".

He also uses a very graphic simile to explain what he means: "If you are moving house, it isn't the same to bring the boxes bit by bit as to have them arrive all at once on the same day, but that is what we do with this unhealthy snacking. If all the food comes at once, you take the boxes to the storeroom (you store fat, in this case) and there they will stay for some time," he explains.

As well as eating healthily, when we eat also has an influence on the health of our body. And that isn't so much to do with leaving a certain number of hours between meals as with not altering the circadian cycle. And this cycle indicates that it is better to eat during the day and rest at night.

"Metabolically, we are 'made' to take advantage of food during the day rather than at night," says Ángel Luis Abad González, endocrinologist and coordinator of the Clinical Nutrition and Dietetics Unit at the Doctor Balmos general university hospital in Alicante.

"When we get up, it stimulates cortisol and carbohydrates are used more effectively. In the first half of the day our sensitivity to insulin is higher and it falls as the day goes on, in such a way that if we give the body carbohydrates at night we will be 'loading' it up because we are more insulin resistant at that time," he explains.

– If we're going to eat something sweet, is it best for breakfast rather than at dinner?

Abad: We never need to consume sugar, but it is true that it is metabolised better in the morning. There is some truth in the saying 'breakfast like a king, lunch like a prince and dine like a beggar'. It is better to have carbohydrates in the morning because they give us quick energy and we are going to make better use of them. Then at night it is better to eat vegetables because they provide fibre and interesting nutrients. And protein should be present in the three main meals of the day.

– And at what times of the day should we eat?

Abad: A gap of three to five hours between eating seems enough. The best time to have breakfast is between 7 and 9am, lunch from 1 to 2pm and dinner no later than 9pm. If we want lunch and tea, then they should be at 1pm and 5pm for example. There are studies that show that people who have lunch after 3pm, even if they consume the same amount of calories as people who eat earlier, put on more weight.

However, apart from the times of meals, Dr Pita points out that "if the total number of calories from food is higher than the amount burned through exercise, this will lead to progressive weight gain".