The effects of hunger and malnutrition

Hunger is defined as an uncomfortable or painful physical sensation caused by insufficient consumption of dietary energy. We know it as the pangs we get when we don’t eat, or don’t eat enough. But when does this go from being an uncomfortable feeling to a global crisis? 

When hunger becomes chronic (i.e., when a person doesn’t get enough food on a regular basis), a host of issues follow in its wake. These can have fatal consequences for individuals, but they can also lead to issues that carry across communities, countries, and international borders. 

From children and adults to societies and our global community, these are eight areas where the effects of hunger have the largest impacts. 

We’ve all felt at least some of these physical symptoms when we’ve gone too long without eating. Headaches, dizziness, fatigue, and feeling weak are all signs that our body is going through energy withdrawal and that we need to refuel. 

There are also the mental, cognitive, and emotional symptoms of hunger, including difficulty in concentrating, irritability, anxiety, confusion, brain fog, and a bad short-term memory. All of these symptoms generally go away once we’ve had time to eat and digest.

Even these symptoms, however, can lead to longer-term effects. People who are unable to afford to eat enough nutrients each day may lapse into chronic variations of the above. Let’s take a deeper look at some of the long-term effects of hunger. 

You might remember from school that the mitochondria is the powerhouse of the cell. That’s because it’s the part of a cell that breaks down food molecules and turns them into energy.  

Mitochondria break down fat molecules into fatty acids, protein molecules into amino acids, and carbohydrate molecules into glucose. These three molecules become the energy currents for our cells, and when we run out of one our body turns to the others.

Stored in the liver, the body uses glucose as its primary energy source. Glucose burns the fastest, meaning that the energy is readily available. Certain parts of the body (like red blood cells and the central nervous system) rely exclusively on glucose. Other parts, like the brain, rely on it heavily as well. 

After 12 to 16 hours of not eating, the body will run out of its glucose reserves and turn to burning fat for energy. This is a stage you may know as ketosis. During ketosis, energy levels begin to drop as fat takes longer to process. The lack of glucose also means that brain fog increases and the central nervous system slows down. 

Depending on how much fat the body has, the body will then turn to muscle and protein for fuel. This can happen within a few days for bodies without a lot of fat. Within a week of fasting, muscle mass begins to drop significantly, as does bone mass. 

As a last resort, the body will turn to breaking down its own organs for fuel. This can lead to irreversible damage to major organs, if not complete failure and death. At this point, a person’s immune system will weaken to the point that they can’t fight off illness or heal wounds. It’s this vulnerability to infections that usually leads to a person starving to death moreso than the actual lack of food itself. 

Children go through the same stages of hunger into starvation as adults. However, because their bodies aren’t fully developed, they’re far more vulnerable. (The same is true for the elderly and immunocompromised.) 

Immune systems are among those that aren’t yet developed, leaving children far more likely to become sick or infected as their bodies go through the phases of starvation. This is one of the reasons that famines can become so deadly: It’s not just about hunger; it’s also about the prevalence of illnesses and other physical risks that will be compounded by the effects of hunger.

If a child survives malnutrition, they can still face a lifetime of repercussions. The first 1,000 days of a child’s life are especially key to ensuring the proper development of their body and organs. If something goes wrong in this time, the effects of hunger may lead to stunting, wasting, compromised organ function, a weakened immune system, and other chronic diseases like diabetes and hypertension. 

In 2018, researchers at Canada’s University of Guelph proved that hanger isn’t just a buzzword. Depleted glucose levels lead to increased stress and depression. Thomas Horman, who led the study, writes: 

There’s also the overall psychological distress of food insecurity. Multiple reports have established a link between food deprivation and both anxiety and post-traumatic stress disorder, even after a family gains food security. 

The mental effects of hunger also extend to education, especially for children. One study from 2022 surveyed nearly 338,000 students across 95 countries. It’s one of the most significant studies of its kind, and it paints a clear picture of how hunger affects learning.

Across countries, undernourished students had lower grades, more absences, and poorer memory-retention. They faced more incidents of bullying, chronic loneliness and worrying, and high-risk behaviors.

Hunger’s effects go beyond individuals and families. Communities and even entire countries can suffer more during a hunger crisis. 

Conflict leads to hunger, but hunger can also lead to conflict. As violence escalated in Haiti through 2019, for example, the UN predicted a nearly 10% increase in hunger levels for 2020. By the beginning of 2021, the increase in Haitians without adequate food was closer to 20%.

Hunger is a key cause of forced migration, influencing a family’s decision on when and where to move. In some cases, fathers and older sons will leave in order to make money to send home, creating a knock-on effect of challenges for those they leave behind. In other cases, entire families will move and live in tenuous circumstances. 

When hunger reaches crisis levels, the resources needed to address it often go beyond what local infrastructure can offer. Health systems are overwhelmed with nutrition-related cases — as well as other diseases. 

In countries with high rates of hunger (many of which also have high rates of poverty), hunger can have an effect on the national economy. In Ethiopia, for example, it’s estimated that hunger contributes to GDP losses as high as 16%.

The second of the UN’s 17 Sustainable Development Goals is to end hunger, achieve food security and improved nutrition, and promote sustainable agriculture. It’s second only to ending poverty, and it’s a key goal because so many of the other SDGs hang on ending hunger and improving both food and nutrition security. 

Quality education (Goal Number 4) will be difficult to achieve if students can’t focus in class because they’ve skipped breakfast and lunch. Promoting peaceful and inclusive societies (Goal Number 16) will also be impossible without resolving the food disparities that often lead to conflict. 

These goals depend on one another to be achieved, and food security is one of the key lynchpins to ensure that both the causes and effects of hunger are mitigated. 

Like the cycle of poverty, hunger can also be cyclical, passed on from one generation to the next. Malnourished mothers have a higher risk of giving birth to babies with more health challenges, including low weight and nutrient deficiencies. 

Children who are stunted (low height for age due to malnutrition) are statistically more likely to become adults with reduced earning potential. This means they’re at a higher risk for living in poverty, perpetuating hunger as they have their own families. It’s a vicious cycle, but it’s also one that we can break. 

We won't end poverty until we end hunger. Stark evidence now demonstrates the enormous scale of nutritional issues in low-income countries, as well as their human and financial costs. As a result, Concern — like many other NGOs, as well as governments and UN agencies, has made unprecedented commitments to prioritise nutrition in our work around the globe. 

Currently, our nutrition strategy is to focus efforts on reducing hunger and malnutrition among adolescent girls, women of reproductive age, and children under the age of 5. We work with adolescent girls to understand how to take care of themselves and advocate for their health and nutrition so that those who eventually become mothers bring a solid nutritional foundation to their pregnancies. We do the same with pregnant and lactating mothers, working with them to track and maintain their vitamin and nutrient levels. Some of our projects focus specifically on the first 1,000 days between conception and a child’s second birthday to prevent malnutrition in this critical time. Other programmes, like Community Management of Acute Malnutrition, screen and treat children up to the age of 5 (and even older) with overwhelmingly positive results and standard-setting cure rates. 

A few other ways Concern fights hunger include: 

• Supporting nutrition-sensitive agriculture and crop diversity to ensure that families have the full range of nutrients they need
• Promote nutrition-sensitive social protection and natural resource management, placing nutrition and health at the forefront of responses to other emergencies such as climate change and conflict
• Working towards gender equality and gender transformative programming
• Working towards improving access to water and sanitation services, while also promoting optimal nutrition, health, and hygiene behaviors
• Increasing access to quality education, especially for girls
• Strengthening local and national health systems so that they can deliver integrated nutrition services (such as CMAM) without ongoing support from Concern