What Are The Early Signs Of Malnutrition?

Malnutrition occurs when an individual doesn't have the nutrients they need to function, which includes the amount of protein and calories they need to give their body energy, though it also means micronutrients like vitamins and minerals. When someone's diet is unbalanced, they might get enough calories without getting enough nutrients. Overnutrition is also a form of malnutrition and occurs when an individual takes in too many nutrients, causing their body's metabolism and functioning to become unbalanced. Different types of malnutrition present with different symptoms. Certain vitamin deficiencies have hallmark symptoms that might present even if an affected individual is taking in enough calories.

Reduced Appetite


A reduced appetite is one of the most common signs of undernutrition. When the body isn't getting the calories it needs, the individual's metabolism will slow down. This means they will expend less energy and require fewer calories to maintain their body. Though this protects against starvation, long-term shifts in metabolism like this will make individuals more likely to gain weight in the long run, which is why crash dieting and highly restrictive diets are unlikely to result in long-term weight loss.

Affected individuals might lose interest in food and drink. It might become difficult to eat large portions because the stomach has reduced the amount of matter it can hold at one time. Trying to eat the same amount as the average person may cause intestinal distress. Children who have a reduced appetite due to malnutrition are at a higher risk of stunted growth. Children need to take in a certain number of calories for their bodies to develop healthily. An unexplained reduction in appetite can also be a sign of an underlying health problem.

Chronic Fatigue


Malnutrition can lead to chronic fatigue, which is one of the most common signs of malnutrition. When individuals don't consume enough calories and protein, their muscles and brain don't have the energy they need to function. It's common to feel physical fatigue and pain in the muscles. It's also common to sleep more than the average person, take naps, and constantly feel exhausted. Various micronutrient deficiencies can also lead individuals to tiredness and an inability to concentrate. They can experience impaired cognitive function and even potential brain damage if the nutrient deficiencies last for too long. 

Fatigue can be caused by other underlying medical conditions as well, some of which can be potentially life-threatening if left untreated. Some of the most common nutritional deficiencies that lead to fatigue are lack of iron, vitamin B12, folic acid, potassium, and magnesium. Iron is the most common nutritional cause of fatigue. Individuals are more likely to suffer from an iron deficiency if they follow a vegetarian or vegan diet, so it's important to make sure they have some iron sources in their diet.

Weight Loss


Weight loss is a common sign of undernutrition. When an individual stops taking in as many nutrients as they need, they often experience a sudden and dramatic loss of weight, though this typically happens unintentionally. Most researchers agree a loss of five to ten percent or more loss of an individual's body weight over three to six months is indicative of malnutrition. Even if an individual is dieting, losing this much weight can be a sign they aren't getting the vitamins and minerals they need. Such a dramatic shift in body weight will slow down an individual's metabolism, which means they're more likely to gain excess weight in the long term. 

Malnutrition is sometimes caused by an underlying health condition that causes malabsorption of nutrients. If an individual's body isn't absorbing all the calories and vitamins in their food, they can experience malnutrition symptoms even if they eat a balanced diet. If individuals experience dramatic weight loss without changing anything about their diet or exercise habits, they should talk to a doctor.

Increased Length And Frequency Of Illness


Malnutrition can have a serious effect on an individual's immune system. When their immune system is impaired, individuals can't off illnesses as easily. They'll be more likely to get sick because viruses and other infections will have an easier time taking root in their body, and they'll have a longer recovery time. This can make individuals feel even more fatigued than they already do. It's a vicious cycle since fatigue also impairs the immune system. Researchers have drawn correlations between immune function and malnutrition that suggest immune suppression can both cause and be caused by malnutrition. 

Undernourished children who die typically perish from common infections. Immune deficiencies have been reported systemically in cases of both overnutrition and undernutrition. When a parent is malnourished during pregnancy, it can affect their infant's metabolic and immune system genes. Malnutrition can also be made worse by inflammation and recurring infections because these alter the function and structure of the gut. Malnutrition impairs certain vital immune cells from functioning properly.

Feeling Cold Frequently


Many individuals who are malnourished also feel cold frequently. They might feel like they can't retain body heat. If they aren't by a source of warmth like a heater, they might constantly feel cold, even if they're covered in insulating clothes and blankets. Individuals may also not get hot on hot days. Feeling cold can also be a sign of other issues, one of the most prominent being thyroid dysfunction. 

One of the reasons individuals might feel cold because of malnutrition is due to anemia, which occurs when individuals don't have enough red blood cells, or the red blood cells they have aren't functioning adequately. Iron deficiencies are among the most common causes of anemia, with B12 deficiencies being right behind. Anemia can be diagnosed through blood tests. In addition to anemia, malnutrition can cause other mineral and vitamin deficiencies that might affect an individual's ability to regulate their body temperature.

Delay In Wound Healing


The body requires carbohydrates, proteins, minerals, and vitamins to adequately heal wounds. Without energy and nutrients from food, the systems inside the body can't work together to heal injuries in a timely manner. Just one nutrient deficiency can have a serious impact on wound healing, depending on the substance. Multiple nutrient deficiencies and lack of calories can be disastrous. Researchers have also found through statistical analysis that malnourished individuals have an increased risk of infection and decreased tensile strength in their wounds. 

Some malnourished patients develop infections due to a sluggish immune system, pressure ulcers due to cardiovascular issues, and slow wound healing due to compromised clotting factors. This can cause wounds to become chronic instead of healing. When a wound is chronic and doesn't heal, the chances of serious infection and other complications are much higher. Chronic wounds greatly increase mortality rates, especially in malnourished individuals whose immune systems are struggling to compensate.

Concentration Issues


One common sign of malnutrition is dealing with concentration issues. It can be hard to pinpoint malnutrition as the underlying cause, though, since many medical conditions can lead to focus issues. The lack of energy from not eating can lead to 'brain fog,'; which makes it harder to process information, commit facts to long term memory, follow instructions, and remember how to do tasks. This is without even considering how many different vitamin and mineral deficiencies can affect an individual's ability to concentrate even if they have consumed adequate calories. 

These problems are particularly concerning for children, since they can have implications for their ongoing neurological development. Undernourished children are more likely to perform badly in school and fail to learn. An iron deficiency can contribute to concentration issues by creating fatigue and a weakened immune system. Chronic iron deficiencies can stunt a child's physical and intellectual development. Meanwhile, chronic iodine deficiencies in children can cause permanent brain damage that leads to learning disabilities. Vitamin B deficiencies can also slow thought processes and impede mental connections.



Malnutrition has been linked with depression in multiple studies for a few potential reasons. One is the lack of nutrients prevents the brain from generating the energy, connections, and neurotransmitters than it usually should, which can lead to lethargy, listlessness, unhappiness, and loss of interest. Other reasons for the connection include external circumstances and shared underlying causes. For example, individuals in impoverished communities suffering from the stress and pain of chronic malnutrition are more likely to feel unhappy and helpless. 

One study showed elderly individuals in rural communities can sometimes feel isolated and become depressed, which leads to a loss of interest in eating, which leads to malnutrition. Some individuals also become malnourished due to eating disorders, which are often exacerbated by depression or share an underlying chemical component with depression. This becomes a vicious cycle, since the sadness from the lack of energy leads to an increased desire to restrict food. Individuals who are malnourished due to eating disorders need mental health treatment just as much or more than they need food.

General Weakness


Malnutrition is one of the biggest possible contributors to general weakness in the body. When individuals eat, their body uses energy in the form of carbohydrates and fats. The fats are used for energy right away, while any excess carbohydrates are converted into fat cells and stored for later. If individuals aren't taking in enough food, their body will begin breaking down its fat stores. It will also start breaking down their muscle and use that for energy. Individuals experience deeper weakness throughout their body and a shrinking ability to complete tasks. 

Even without taking the muscle shrinkage into account, the lack of energy in the body means individuals will be too tired to complete tasks. Some may collapse when they try to stand or walk any distance, since they simply don't have enough energy to keep their brain conscious and their body moving. A lack of protein has a significant impact on muscles, since the body has nothing to feed and strengthen them with.

Behavioral Changes


Behavioral changes can occur as a result of malnutrition, though the exact presentation and reason for this varies. In severe cases, malnutrition and nutrient deficiencies might lead to neurological symptoms like severe emotional instability, hallucinations, paranoia, irrational behavior, and extreme and unwarranted anger. Individuals experiencing sudden and unexplained behavioral or personality shifts should be evaluated by a doctor right away. There are other cases where behavioral changes are more gradual, though, especially in children. Malnutrition leads to a significant increase in overall stress, especially if it's also impeding performance in school or at work. 

The stress and hopelessness can manifest in volatile external behaviors, particularly for children who are still developing their ability to emotionally self regulate. Researchers have found children who exhibit aggressive behavior, extreme anger, hyperactivity, and inordinate defiance toward authority have a much higher incidence of malnourishment at home. In addition to stress, researchers believe malnutrition has neurological effects on children, chiefly that their neurons are reduced and neurotransmitters are unable to function properly. This predisposes them toward recklessness, impulsivity, volatile emotions, and hyperactivity.


    Katherine MacAulay