To feed and nourish oneself is, together with to hydrate and to breathe, one of the most basic needs not only of the human being but of all living beings. In the case of our species, we need to eat in order to acquire enough nutrients for our organism to function and survive.

However, there is a high percentage of the world’s population that does not have access to enough food to live on or is not able to process and use the nutrients in it. These people are or will be undernourished, with a range of consequences of varying severity. In this article we are going to talk about the effects of malnutrition , as well as its concept.

Malnutrition: basic definition

As indicated by the World Health Organization, the existence of a lack of food or of the amount of calories, nutrients, vitamins and minerals necessary to preserve a correct state of health, being this state in accordance with what is expected based on the age of the individual, is called malnutrition.

In other words, there is a lack of sufficient nutrients in the body to maintain optimal levels of functioning. The absence of sufficient nutrients will generate the consumption of internal energy reserves (and if necessary, the organism will consume its own tissues to survive), leading to a progressive weakening of the organism that may even lead to the death of the subject.

Types by cause

The concept of malnutrition can be easily understood, but it is necessary to take into account that in reality we can find different types of malnutrition, although the effects on the organism are similar . One of the existing classifications takes into account where the lack of nutrients comes from, generating two main categories.

In the first of these, the so-called primary malnutrition, the person is deficient in nutrients due to insufficient food or starvation. This lack of nutrition can occur in a variety of contexts. The most obvious case can be found with people who do not have access to sufficient food such as in countries with famine and high levels of poverty.

Another type of situation in which primary malnutrition appears is that of people who, despite living in a context in which they can access enough food, do not take it in , which is the case of eating disorders such as anorexia nervosa .

A second type of malnutrition is the so-called secondary malnutrition, in which the subject does make an adequate intake and eat enough but because of some disorder or disease is not able to metabolize the nutrients. This implies that these nutrients are not integrated and used by the body, something that will also generate adverse effects on health.

Effects of malnutrition

The lack of nutrients has considerable effects on the body, which can even lead to death in people of any age, race or condition if not enough essential elements are available to keep the organs functioning. In most human beings, malnutrition can cause effects such as the following, although the ones we are going to present are not the only ones.

1. Changes in body weight and volume

One of the most quickly visible aspects of malnutrition is that there is considerable weight loss. However, if the malnutrition situation is prolonged and affects hormones such as insulin and glucagon , it is possible that some abdominal obesity may appear, derived from the alteration of food metabolism.

2. Loss of muscle mass

In the absence of sufficient protein, the body acts to protect its survival by extracting energy from the body’s own fibres, for example by consuming the muscle fibres in the so-called protein catabolism .

3. Hypotonia and decreased energy levels

Another consequence of the lack of nutrients is decreased muscle tone, with less muscle tension and strength. Also a great decrease in physical and mental energy is observed .

4. Bone fragility

As with muscle, bones are also affected by malnutrition. They become more fragile and brittle , being more likely to be injured and broken.

5. Amenorrhea

The menstrual cycle is also affected by malnutrition, with a lack of nutrients leading to irregularities and even the cessation of periods.

6. Weakening of the immune system

One of the most affected by the loss of nutrients is the immune system. A weakness is generated in this system that makes it difficult to respond to bacteria and viruses , making it much easier for infections and diseases to appear.

7. Dental irritation and bleeding

Dental problems are also observed, often presenting gum irritation and even bleeding.

8. Edemas

It is common that the lack of nutrients and the existence of electrolyte imbalances derived from insufficient nutrition causes the accumulation of liquids in different parts of the body , generating swelling in the form of edema.

9. Cardiovascular alterations

The lack of nutrients weakens the heart muscle and blood vessels, which can lead to arrhythmias, hypotension, heart failure and death.

10. Decreased gastrointestinal functioning

Not having enough nutrients for the body to function properly also affects the digestive tract , making it unable to act properly. In fact, a person with prolonged malnutrition cannot start eating normal amounts at once and must gradually adapt in order for the intestinal motility to return to its normal course.

11. Impaired cognitive ability

Malnutrition also affects the nervous system to a great extent. At the cognitive level, it is common for alterations to be generated in the cognitive capacity, reducing the emission of elaborated responses, the capacity to plan and make decisions , the judgment or the capacity to concentrate or inhibit behaviour.

12. Emotional Ability, Irritability and Mental Problems

Lack of nutrients affects behavioral inhibition capacity and facilitates attack/runaway responses. Emotions surface more easily than usual . Problems of irritability, anxiety or depression are much more frequent.

13. Affects respiratory capacity

It can cause problems in our body’s ability to oxygenate itself and expel carbon dioxide.

14. Slows down metabolism

When the body realizes that it does not have enough nutrients to function properly, it proceeds to try to reduce the metabolism in order to save energy .

15. Pancreatic and liver dysfunctions

The liver and pancreas are also affected by malnutrition, unable to purify the blood or generate insulin and glucagon and altering the functioning of the digestive system.

16. Kidney problems

The ability of the kidneys to act as a filter for the blood and to remove waste and harmful elements is also affected. The lack of nutrients hinders their function, not filtering these elements correctly.

17. Anemia

One of the consequences of nutrient deficiency is the development of anaemia, i.e. the reduced production of red blood cells due to a lack of basic components such as iron or vitamins. It causes dizziness, fainting, headaches, arrhythmias, pallor, numbness and lack of blood supply in some parts of the body.

Malnutrition in children

So far we have talked about different effects of malnutrition on the human being in general. However, it has been demonstrated that the evolutionary moment in which malnutrition appears is of great importance .

Specifically, the earlier in the evolutionary development, the greater the effect it will have on the subject. The difficulties due to lack of nutrients during development will cause this to be altered and not reached at a typical rate or in a typical way, asking you to stay for life some sequels.

Child malnutrition is one of the most serious, since it slows physical and intellectual development. For example, growth in weight and height often stops and psychomotor retardation and speech problems may appear, as well as difficulties at the attention level. Ventral swelling and hair problems also appear. The growth of the brain is slowed down and atrophies, reduced number of glial cells and myelinization problems may occur.

Bibliographic references:

  • Martorell, R. (2007). Effects of malnutrition on health and human development and effective strategies for its prevention. Public Health of Mexico, 49: 151.
  • Smith, L and Haddad, L. (1999). Explaining Child Malnutrition in Developing Countries: ACross-Country Analysis. FCND discussion paper 1999 (60) IFPRI, Washington, D.C.
  • Wisbaum, W. (2011). Child malnutrition. Causes, consequences and strategies for its prevention and treatment. UNICEF.