Understand how chemistry helps to eat strategically at the New Year’s Eve party

The traditional end-of-year festivities can be an opportunity for overindulgence when it comes to eating. Knowing the chemical composition of food can help to avoid some of these excesses that can be harmful to health in addition to causing discomfort the next day.

One of the ways to control what we are going to absorb after eating is to know what the food fibers in which order to ingest them and how they work during digestion.

Dietary fiber can be divided into two groups: soluble and insoluble as explained by Professor Marcos Buckeridge, from the Institute of Biosciences at the University of São Paulo (USP).

“The vast majority of dietary fiber comes from plants and consists of sugar polymers (polysaccharides) that are found in the cell walls of all plant cells. So, let’s understand better: insoluble fibers constitute polysaccharides such as cellulose and hemicelluloses, which, due to their strong interaction with each other, do not easily dissolve in water. Pectins (important components in fruits), on the contrary, dissolve relatively easily, even in cold water, and are, therefore, part of the group of soluble fibers”, he explains.

Differences in fiber types

According to the specialist, the functions of these two types of fiber in food are distinct in the foods we consume.

“The way they are prepared also makes a difference. We can consume fresh fruit or fruit juice, tomatoes in salad or tomato sauce. Even coffee has fiber and the way it is prepared also makes a difference”, he adds.

At insoluble fibers have a more pronounced mechanical function and serve to give greater consistency to the food bolus. Without this type of fiber, humans would probably be able to digest very little of the food we eat and remain in a state of constant diarrhea.

“The other extreme, that is, an excess of insoluble fibers, would cause constipation, as the bolus would become more and more solid. Therefore, we humans are adapted to ingest a certain balance of soluble and insoluble fibers in such a way as to keep the transit of food through the digestive system imperceptible. It is important to have a balance between the foods consumed”, he points out.

already the soluble fibers actively participate in the mechanical function , but in addition, due to their higher solubility in water and high viscosity, they hinder the movement of molecules within the food bolus. The USP professor explains that, for this reason, these fibers “capture” part of the simple sugars and fats, and prevent them from being absorbed in excess.

“It is believed that when we eat fiber, a viscous layer forms on the inner surface of the intestine, called the non-agitable water layer, which has the function of ‘filtering’ what is absorbed. Whether this effect is good or bad for those who ingest fiber depends on how much and what type. It also depends on the order we adopt to eat during meals”, he says.

Supper time strategies

Starting with the salad makes sense , according to the expert. As the leaves have a good mix of insoluble and soluble fibers, these materials will not only provide better physical support to the food bolus, but with the soluble fibers rich in pectin, they end up helping to form a layer of non-agitating water, creating a kind of filter that controls the absorption of what comes after.

“With this, it is already known that eat fiber before candy that come with dessert , the spike in blood sugar will be lower. The same goes for fats. This is because the complex structure of cell wall polymers forms a network that captures smaller molecules. O coffee at the end of the meal will add more soluble fiber and so much the better if it is unsweetened”, he says.

Fruits contain more soluble fiber while leaves and roots contain more insoluble fiber. The seeds generally have a balance between the two types of fiber, explains the professor.

In the case of fruits, in general, there is an intake of a greater amount of sugars, which will be balanced in the intake by the large amount of pectins (soluble fibers). Seeds, on the other hand, have other characteristics: they store proteins or fats and insoluble fibers end up modulating digestion in another way.

“We still have to remember that everything changes if the food is cooked. In this case the proportion of soluble fibers becomes higher. In the case of processed foods such as ice cream, yogurt and ready-to-eat soups, there is always the addition, even in small amounts, of polymers that function as fibers”, he concludes.

In short:

1. fibers are in the cell wall of plant cells and have diverse chemical composition and properties,
2. Fibers can be divided into two major groups: soluble and insoluble,
3. the insoluble ones correlate more with mechanical function and the fibers help to form viscous layers in the intestinal walls: the non-agitable water layer,
4. cooking can alter the ratio of soluble and insoluble fiber in a given food.

(With information from the Journal of USP)