You ate it this morning and you didn't know it: the mistake that can worsen your metabolic health
Endocrinologist Francisco Rosero warns about the risks of consuming bread at breakfast, especially in people with metabolic issues.
Bread at breakfast. A custom as everyday as it is universal. Toast with tomato, ham sandwiches, or bread with butter have been the first bite of the day in millions of homes for decades. But what happens when such a normalized habit could be silently harming your health?
The endocrinologist Francisco Rosero has been blunt in a recent interview: “Eating bread at breakfast is very harmful for those with metabolic issues.” His warning is not based on trends or assumptions, but on clinical evidence and professional experience. Breaking the fast with bread, whether white or sourdough, can have adverse effects on the body, especially in people with conditions such as insulin resistance, diabetes, obesity, or fatty liver.
According to data from the association Pan Cada Día, 92.6% of the Spanish population consumes bread regularly. Of these, more than 75% prefer white bread. Seven out of ten Spaniards consume between half a loaf and a slice daily, and a large portion does so at breakfast. Although culturally accepted as part of a balanced diet, experts warn that its consumption on an empty stomach is counterproductive.
Why bread is not the best way to break the fast
After several hours of overnight fasting, the body enters a particular metabolic state. Insulin levels are at their lowest, allowing for more efficient use of fat reserves as an energy source. However, when consuming bread at that moment, a sharp spike in blood glucose occurs, leading to an intense insulin response.
“This sudden increase in insulin not only halts the natural fat-burning process,” explains Rosero, “but also promotes the storage of energy in the form of body fat.” In other words, just when the body is ready to burn fat, we provide it with a food that forces it to store even more.
This mechanism can be particularly harmful for people with metabolic issues. In those suffering from insulin resistance, for example, this glucose spike is harder to control. The pancreas is forced to work harder to secrete insulin, which can accelerate the deterioration of its function over time. Additionally, elevated glucose levels can persist longer, causing chronic wear that favors the onset of complications such as type 2 diabetes.
How bread affects fatty liver and obesity
The habitual consumption of white bread also exacerbates conditions such as non-alcoholic fatty liver, a disease affecting an increasing percentage of the population. This condition is characterized by the accumulation of triglycerides in liver cells, and one of the major risk factors is the excess of refined carbohydrates, such as those found in white bread.
The body quickly converts simple carbohydrates into glucose. If that energy is not used immediately, it transforms into triglycerides that are stored in the liver and adipose tissue. Thus, a breakfast based on bread can silently fuel a process that ends in overweight, liver inflammation, and cardiovascular diseases.
White bread, whole grain bread, and sourdough: are there differences?
The belief that certain types of bread are healthier has gained traction in recent years. Sourdough bread, for example, has been promoted as a “more nutritious” alternative due to its fermentation process and artisanal flavor. But Rosero clarifies: “The differences between white bread and sourdough are minimal from a metabolic standpoint.”
Both types of bread contain around 55 grams of carbohydrates per serving, and their glycemic index is quite similar: 70 for white bread and 60 for sourdough. Although this reduction might seem favorable, it does not represent a substantial advantage for those who need to control their glucose levels.
In terms of fiber, sourdough bread offers 4 grams per serving compared to 2 grams in white bread. However, that small increase does not offset the negative effect of the high carbohydrate content. Additionally, its caloric contribution is practically the same, debunking the idea that it is a lighter or more diet-friendly option.
Another important point is the presence of gluten. Although the slow fermentation of sourdough partially breaks down this compound, it remains problematic for individuals with gluten sensitivity or intolerance, even if they do not have a diagnosis of celiac disease.
What do experts recommend for breakfast?
Instead of bread, Rosero suggests foods that promote glycemic stability, satiety, and sustained energy. Here are some of the best options for breaking the fast healthily:
- Eggs: rich in high-quality protein and healthy fats.
- Avocado: a source of monounsaturated fats and fiber.
- Unsweetened natural yogurt: improves gut flora and provides protein.
- Nuts: a good source of energy, healthy fats, and minerals.
- Cooked or steamed vegetables: ideal for accompanying other foods.
This type of breakfast activates metabolism without sharply raising insulin, prolongs the feeling of fullness, and helps control appetite throughout the day. Additionally, it keeps blood glucose levels stable, which is crucial for those looking to prevent or manage metabolic diseases.
A little-known trick: vinegar and bread
Although the main recommendation is to avoid bread as the first meal of the day, Dr. Carlos Andrés Zapata offers an interesting tip: “Adding vinegar to bread can decrease the sugar spike by up to 40%”. This practice, supported by some studies, shows that acetic acid has a modulatory effect on carbohydrate absorption.
Eating bread and glucose: the detail that puts your internal balance at risk
However, this does not make bread a healthy food for breakfast, but it may partially reduce its negative effects when consumed at other meals. Still, moderation remains key, and prioritizing other types of foods at breakfast is the most advisable for those looking to care for their metabolism.
The conclusion of the experts
What seems like an innocent decision every morning —spreading jam on a toast— could be influencing our long-term health more than we imagine. While bread can have a place in the diet, breaking the fast with this food is not the most advisable, especially if there is a history of diabetes, obesity, or fatty liver.
Therefore, before preparing your breakfast tomorrow, remember these warnings. It may not be about completely eliminating bread, but rather choosing better when to consume it and, above all, stopping using it as the food that starts your day.