The optimal breakfast provides 25% of the daily calories

Breakfast is the most important meal of the day. This is an often repeated saying. However, little is said about how it should be. The project led by Álvaro Hernáez of Montserrat Fitó’s group (Hospital del Mar Research Institute) has studied the influence of the quantity and quality of breakfast on our health. In their latest article, they publish that a breakfast that provides between 20 and 30% of the daily energy improves metabolic and cardiovascular health indicators and reduces obesity.

This observational study was conducted as part of the PREDIMED-Plus trial that looked at how the combination of Mediterranean diet and exercise promoted weight loss in people aged 55-75 years. The breakfast study drew on data collected during PREDIMED-Plus to look solely at the effect of breakfast on health improvement. Specifically, a reduction in abdominal obesity and triglycerides and an increase in good cholesterol (HDL) were seen.

In this case, the eating routines of around 400 people in both the control group, which only followed the Mediterranean diet, and the intervention group, which also exercised, were analysed over three years. The results were normalised to each patient’s lifestyle to isolate the contribution of breakfast. Álvaro notes that ‘everyone improved their indicators, as they were within a specific intervention. However, it was seen that those who had a higher quality breakfast, with a caloric intake of 20-30%, improved more.’ Patients who regularly ate too little or too much breakfast had worse indicators.

A balanced breakfast is a must

It is difficult to specify what constitutes a breakfast, let alone a quality one. Here, breakfast was defined as any food taken before lunch. This included having, for example, a coffee when you first get up and then a mid-morning snack. This was done because not everyone has an appetite when they get up or time to prepare a proper breakfast when they rush out of their house to work.

What Álvaro, Alejandra Pérez-Vega (first author of the article) and the rest of the researchers of the study saw is that regardless of whether it was spread out over time or eaten in one sitting, if breakfast provided the necessary amount of calories and the right nutrients, it improved the quality of life of all patients. However, they stress that the results cannot be extrapolated to the rest of the population, as the study focused on a group of people with metabolic syndrome, a set of cardiovascular risk factors that occur at the same time.

‘People must take care of the quality of their breakfast and adapt it to their timetables and tastes’

Alejandra Pérez-Vega (HMRIB)

This means that it is not possible to draw specific recommendations for the whole population. For that, a more exhaustive study would be needed. However, both Alejandra and Álvaro do dare to give some general recommendations. Both agree that it is important to have a balanced breakfast, with wholegrain cereals, fruit, healthy fats such as olive oil or nuts, and quality proteins. They also say that breakfast should not be skipped and, above all, ultra-processed foods should be avoided.

In this regard, Álvaro complains that when people talk about a balanced diet, guidelines are usually given for lunch and dinner, but not for breakfast. In addition, he stresses that people are aware of the harm of ultra-processed foods and tend to avoid them at lunch and dinner. However, whether due to lack of time, convenience or taste, ultra-processed foods are a common breakfast staple.

Next steps

After these results, the group would like to corroborate them with a clinical study. In this way, they would be able to see whether the amount of energy breakfast should provide is the same for the whole population or whether it varies according to age, for example. With the clinical study, they would also determine whether the observed results are really caused by the amount of energy ingested at breakfast or whether it is just a correlation.

In addition, they want to go further and see how breakfast influences other diseases. Right now, they are looking at the relationship between the first meal of the day and cancer. To do this, they need to secure funding, a task that is not always easy. Nutrition is a simple discipline, but one where there is a lot of noise, as Álvaro says. Outside the scientific environment, it is full of people selling miracle diets and infallible tricks for taking care of oneself that are, however, dangerous. It is difficult to fight against this oversaturation of information, especially with studies as long as this one.

A very humane study

The analysis of the influence of breakfast on the quality of metabolic and cardiovascular health has been a project carried out entirely by the Hospital del Mar group. From the recruitment of the patients to the analysis of the data, including the regular follow-up. It was an exhaustive fieldwork in which Alejandra was involved practically from the beginning.

It all started with the recruitment of the PREDIMED-Plus project, which took several years to complete. However, they did not wait until they had all the patients before starting the intervention. So the timing between patients was out of sync. While some were already in their second year in the study, others had just entered. This meant that the workload was constant, but not overwhelming, as they did not have to follow all 400 people in the same week, but spread out over the year in order of entry.

‘Patients were very attentive to changing their diet.’

Alejandra Pérez-Vega (HMRIB)

Alejandra particularly enjoyed the human side of the project. Even though she is no longer involved in fieldwork as much as before, she remarks that the most important aspect of this study was the regular contact with the patients during the interviews. This created a bond between them. She also points out that it helped that all the follow-up was carried out at the facilities of the Barcelona Biomedical Research Park (PRBB). Both the interviews and the blood tests were done in the offices and clinical trial rooms at the Hospital del Mar Research Institute, which was easier than if they had been spread over several locations or done at the hospital.

Alejandra’s contribution to PREDIMED-Plus has not only resulted in the conclusions of this article. It has also culminated in the presentation of her doctoral thesis, which she defended in December last year and which will be available for future consultation in the library.