Intestinal problems despite “healthy diet”

Although it may seem that digestive tract problems, such as bloats, flatulence or diarrhea are a result of an “unhealthy diet”, the truth is, that many people experience them despite the fact that they care about what they eat. Why does it happen? And the most important matter – can we avoid it?

You should definitely read:

Hypolactasia and lactose intolerance

The healthy diet paradox

“Tell me why during all these years when I ate a baguette and sausages for breakfast, coffee and cake for second breakfast and a 'takeaway' for dinner from some diner I never had any gastric problems and now that I started eating healthy food I have bloats and flatulence?” - this kind of questions are not so rare at my work. I sometimes meet people who suffer from digestive problems after starting a “healthy diet” prepared by themselves. Such menus are often based on food plans posted on forums, blogs or in magazines, and they contain following products:

  • wholemeal cereal products,
  • lean meat,
  • lean dairy products,
  • vegetables (especially crucifers such as broccoli),
  • olive oil,
  • peanut butter,
  • eggs.

People who suffer from the problems mentioned above chose two ways – they either think that “it's supposed to be this way”, or leave the attempts of new nutrition plans and go back to their old habits. Unfortunately, none of these solutions makes sense. In order to find the solution of the problem, the causes should be understood, and those can be differentiated. In the following parts of this article I will try to explain the “healthy diet paradox”.

Too much “good”

It is a very common rule that if some product is thought to be healthy or valuable, it means it should be eaten every day, and it would be the best – in large quantity. Unfortunately, such attitude leads to digestive problems (among other, sometimes very dangerous). To make this situation clear, wholemeal bread, which is thought to be a more wanted component in a diet than white bread, can be presented here. Sadly, large consumption of “dark” bread usually causes bloats, flatulence and diarrhea. It is connected with high content of insoluble fiber fractions and the presence of fructans, which are very problematic for many people.
The situation may be similar in case of broccoli, which is a great source of antioxidants and fiber, however, when eaten every day in large amount, it may cause flatulence and intestinal discomfort. The reason of this problem is not the presence of such vegetables in diet, but lack of restraint in eating them. There are more products like broccoli, and they may be e.g. legumes, onion, groats, brown rice, and many more. It's worth remembering that when we find a valuable product which caused discomfort, instead of total elimination, we can limit its doses. It often helps.

Key word – lactose

In the infancy period and in childhood we don't usually have problems with digesting milk products, and even consuming large quantities of dairy products does not cause unpleasant symptoms. However, in some period of our lives this matter changes. Body loses the ability to digest milk sugar – lactose. It is connected with lowering the production of lactase enzyme, which “deals” with digesting lactose. As a result, consuming milk and its products causes many unpleasant digestive problems such as:

  • bloats,
  • feeling of overflowing in stomach,
  • flatulence,
  • stomachache,
  • diarrhea.

What's interesting, many people do not realize that milk sugar is the cause of such symptoms in their case. The reason of such situation is that small amount of lactose for majority of society does not cause any symptoms. The amount of sugar milk, which is tolerated by the body, is about 5-12g, which is about 150-250ml. The problems start when more dairy products are eaten. When there is lactose digestion disorder, the best way of getting rid of troublesome symptoms is the elimination or noticeable reduction of dairy products from the diet. Another solution is implementing supplements, which contain lactase. However, this option is recommended for people who have strong reaction after a symbolic amount of milk sugar.

Sugar replacements - polyols

Polyols (alcohol sugars) are usually presented in good light. These compounds, apart from few other features, are suggested as a healthy replacement for sugar. The flag example can be xylitol, i.e. birch sugar. It occurs, however, that polyols have disadvantages. If eaten in excess amount, they can lead to differentiated problems from the digestive tract. But "excess amount" can be considered in many ways, there are people who tolerate well even several dozens of grams of polyols, whereas for others even a symbolic amount can be a problem.
Apart from the mentioned xylitol, other alcohol sugars can be used in food products and they are:

  • sorbitol (E420),
  • mannitol (E 421),
  • isomalt (E 953),
  • sorbitol syrup (E 420),
  • maltitol syrup (E 965),
  • maltitol, lactitol (E 966),
  • xylitol (E 967),
  • erythritol (E 968).

Polyols can be found mostly in sugar-free chewing gums and dietetic confectionery, sports bars (especially low-carb and high-protein), and they are also introduced to diet on purpose as a sweetener instead of sugar (xylitol).

Bad gluten

It's been quite loud about gluten recently. On the one hand, there are people who state that everybody should be attentive to it and the best would be its total elimination from a diet, on the other, such rumors are denied even by scientist authorities who research on gluten subject. Frankly speaking, this problem is quite complex because it occurs, that the gluten problem may concern not only people suffering from celiac disease. Additionally, there is also a disease called Non-Celiac Gluten Sensitivity (NCGS), which concerns about 6% of society.
In case of NCGS consuming products containing gluten may cause e.g. unpleasant symptoms from the digestive tract. It's good to have on mind the fact that products made of white flour are not the only source of gluten, but also products made of rye and barley. Therefore, rye flakes, buckwheat groats, spelt bread and wholemeal noodles from durum flour, as well as many other similar products - are also the sources of gluten. What's more, other raw products, such as oat flakes or buckwheat can be polluted with gluten, too!
You can read more on NCGS in Łukasz Kowalski's article:

Devious fructose

Although the problems with fructose tolerance are more frequent than it may seem, they usually don't show any effects if the supply of this sugar is lower than the consumption of glucose. Taking under consideration that glucose is more widespread sugar, in practice it's hard to lead to noticeable symptoms of fructose intolerance, however, they may occur when:

  • sugar is replaced with fructose,
  • the consumption of products sweetened by fructose (considered as a dietetic replacement for sugar) is high,
  • the main source of carbs are highly-fructose fruits (e.g. apples).

Knowing that the problems with fructose tolerance may concern even 50% of our population, it's worth avoiding this sugar in refined form and trying not to "dominate" the diet with that originating from low-processed food.

Legumes and an unpleasant duet: stachyose and raffinose

It's been known for a long time that eating legumes may cause some unpleasant symptoms from the digestive tract, such as bloats and flatulence. It is connected with the presence of sugars from the oligosaccharide group, such as stachyose and farrinose. Unfortunately, human body doesn't produce any enzymes which could decompose these carbohydrates, therefore, they are a good nutrient for the intestinal bacteria - the production of flatulence starts under their influence.
Of course, legumes can be a very valuable element of a healthy diet because they contain a lot of vitamins, fiber and minerals. However, it's good to stay moderate when it comes to consuming them and treat them thermally (majority of them should be soaked). Thanks to this action most of the anti-nutrients can be neutralized and therefore, the unwanted symptoms from the digestive tract can be reduced.


As it can be seen, a healthy diet based on valuable (or, like in case of fructose - "dietetic") products can be the source of components which influence the work of digestive tract in a negative way. The tolerance of these compounds is highly individual and should be considered also individually. One thing is certain - you shouldn't belittle the digestive tract disorders because, apart from the fact that they are unpleasant, they can also lead to many complications connected with inappropriate development of bacterial flora and disrupted absorption of many important components.