Fatigue can be caused by a variety of conditions, including malnutrition. It's a reduced capacity to act because of a lack of resources. It's a protective mechanism, preventing you from acting when your ability to respond is compromised. In the case of malnutrition, it is also a survival mechanism to keep you from tapping resources you need to live.
Energy Production
You may be fatigued if you are malnourished simply because your body lacks the raw materials it needs for energy production. Several B vitamins participate in energy-producing chemical reactions. Among them are thiamine, riboflavin and niacin. These vitamins are water soluble, meaning that the body does not store them. Rather, your diet must supply them. Malnutrition can easily lead to fatigue if you are not getting these vitamins in your daily diet.
Immune System Function
If your your body is unable to respond to threats from infection, wounds or other agents because of a lack of nutrition, you will likely become fatigued. Vitamins A, C and K all facilitate the healing and repair of damaged tissue. A diet lacking in these nutrients can negatively affect your ability to handle threats. In this case, your malnutrition-related fatigue creates a vicious cycle in which your body's need to repair tissue damage conflicts with the drive to serve basic body functions.
Protective Function
Fatigue can serve as a protective function if you are malnourished. In this situation, you are less capable of getting up and doing what you want to do because you lack the energy. Fatigue is your body's way of keeping quiet so that you don't do something you lack the energy to do safely. This reaction is one of many that reflects biological mechanisms for survival.
Conservation of Resources
Many of the body's functions are driven by survival. When you are malnourished, the body will try to conserve its resources. What nutrients and energy it has, it will direct toward life processes rather than physical activity. The mere act of existing takes energy. Up to 75 percent of your caloric intake is used for basic body functions such as breathing and circulation, according to the Mayo Clinic website. Your body will ensure that you have adequate resources for these activities instead of expending energy on nonessential processes.
References
- Colorado State University Extension; Vitamins: Introduction and Index; R. Bowen; August 16, 2003
- Colorado State University Extension; Water-Soluble Vitamins; J. Anderson and L. Young; August 2008
- Teens Health: Hunger and Malnutrition
- Elsevier Health Services: Nursing Diagnosis: Fatigue
- "Principles of Anatomy and Physiology"; G. Tortora et al; 2005
- Mayo Clinic; Metabolism and Weight Loss: How You Burn Calories; October 6, 2009
