Malnutrition is when a person’s diet does not provide enough nutrients or the right balance of nutrients for optimal health. Causes of malnutrition include: unsuitable dietary choices having a low income difficulty obtaining food various physical and mental health conditions Undernutrition is one type of malnutrition Trusted Source. It occurs when the body does not get enough food and enough necessary nutrients. It can lead to: delayed growth low weight wasting If a person does not get the right balance of nutrients, they can also have malnutrition. It is possible to have obesity with malnutrition. When a person has too little food, a limited diet, or a condition that stops their body from obtaining the right balance of nutrients, it can severely impact their health. In some cases, this can become life threatening. This article looks at malnutrition in detail, including the causes, symptoms, and treatments.