Malnutrition means your body does not get the right balance of nutrients it needs. It includes both undernutrition (not enough needed nutrients) and overnutrition (too many calories, but often missing important vitamins and minerals). Anyone can be affected by malnutrition, not just people who are very thin. In fact, even people who are overweight or obese can be malnourished if their diets are lacking essential nutrients. According to the World Health Organization (WHO), malnutrition is one of the biggest health problems globally and covers a range of issues from being underweight to being overweight and obese. This means many people around the world, including those who are heavy or have obesity, can still have poor nutrition.
The effects of malnutrition are serious and can affect not just individuals, but whole families, communities, and even countries. It can raise healthcare costs, lower work productivity, and keep people trapped in poverty and poor health. Because it is such a big problem, the United Nations made 2016-2025 the Decade of Action on Nutrition, showing just how important it is to fight all forms of malnutrition everywhere.
Who Is at Risk by Age Group?
Malnutrition can affect people of any age. The risk and effects can be different depending on how old you are and your body’s needs at each stage of life.
Infants and Young Children
Babies and toddlers are especially likely to suffer from malnutrition because they need the right nutrients to grow and develop properly. Even a small lack or too much of certain nutrients at a young age can cause long-term problems. In 2022, WHO reported that 149 million children under 5 were too short for their age (stunted), and 45 million were too thin for their height (wasted). Undernutrition in young children is often linked to poor living conditions, mothers not eating well, frequent illness, and wrong ways of feeding. Nearly half of all deaths in children under 5 are connected to undernutrition, with most cases in low- and middle-income countries. On the other hand, 37 million kids under 5 were overweight or obese in the same year, showing that children can have both types of malnutrition at once-too little and too much nutrition.
Adolescents
Teenagers go through a time of quick growth, which means they need more nutrients. In 2022, about 390 million people aged 5-19 were overweight, and 160 million had obesity. Also, 190 million teenagers and older children were too thin. Many face pressure to eat fast food or processed snacks high in calories but low in vitamins and minerals. Sometimes, even if they eat enough or too many calories, they might miss out on key nutrients like folic acid, especially if they have a larger waist circumference.
Adults
Adults can have both undernutrition and overnutrition. In 2022, there were 2.5 billion overweight adults, including 890 million with obesity, but also 390 million adults were underweight. Often, these problems come from eating a lot of processed foods, busy lifestyles, and sometimes existing health issues. Many people are overweight but still miss out on important nutrients-like vitamin D3, B vitamins, vitamin C, magnesium, and vitamin E-because of bad food choices or health problems that keep them from absorbing nutrients properly.
Older Adults
As people age, they can struggle even more to get the right nutrition. Older adults may have difficulty moving, live in care homes, have less appetite, or trouble absorbing food. Chronic illnesses also become more common and can make malnutrition worse. This can lead to weaker immune systems, slow healing, and worse physical and mental health, which means regular checking and help with eating is very important for this group.
| Age Group | Main Risks | Common Forms of Malnutrition |
|---|---|---|
| Infants & Young Children | Poor feeding, rapid growth, infections | Undernutrition (stunting, wasting), Overweight |
| Adolescents | Unhealthy food choices, body image issues | Undernutrition, Overweight/Obesity |
| Adults | Poor diet, sedentary lifestyle, existing illnesses | Obesity, Micronutrient deficiencies, Underweight |
| Older Adults | Difficulties in eating, illness, isolation | Undernutrition, Micronutrient deficiencies |
Which Populations Have Higher Risk?
Anyone can get malnutrition, but some groups are more likely to be affected because of their situation or health status.
People with Low Income or Living Where Food Is Scarce
Poverty makes getting good food harder. People and families with less money often rely on cheap, filling foods that don’t have enough vitamins and minerals. In wealthier countries, poor neighborhoods often have many fast food places but few grocery stores with fresh produce. This means people get plenty of calories but still miss out on important nutrients, so both undernutrition and obesity can show up in the same community or even person.
People with Chronic Illnesses
Long-term sickness can raise the chance of malnutrition. Some diseases cause people to lose their appetite or make it harder for the body to use nutrients. Examples include conditions like inflammatory bowel disease, some cancers, and diseases needing long-term medication. Some medicines also make it harder to absorb nutrients, worsening the problem. Good nutrition is important for people with chronic illnesses, not just for health but because it helps treatments work better.
People with Mental Health Challenges or Disabilities
Mental health problems (like depression, anxiety, or dementia) can change eating habits or make it hard to shop or cook. This sometimes leads to eating too little, the wrong foods, or while in some cases, eating too much. People with disabilities may also have trouble eating, chewing, or swallowing. These challenges mean some need extra help to eat well and stay healthy.
Those in Hospitals or Long-Term Care
Being in the hospital raises the risk of malnutrition; 20-60% of hospital patients don’t get enough nutrition. This can happen if people feel sick, can’t eat normally, or rely on standard meal plans that don’t suit them. People living in care homes may also get less say in their food choices. Recognizing problems early can help improve health and lower costs.
Pregnant and Breastfeeding Women
Pregnancy and breastfeeding demand more nutrients for both mother and baby. Missing key nutrients like iodine, vitamin A, or iron can cause serious problems for their health and the baby’s growth, especially in poorer countries. Getting the right nutrition from pregnancy until a child is age two is very important for a child’s future.
| At-Risk Group | Main Challenge |
|---|---|
| Low-income Communities | Lack of healthy food options |
| People with Chronic Illnesses | Poor absorption or higher needs |
| Mental Health/Disabilities | Eating or preparing food is hard |
| Hospital/Long-term Care | Limited food choices, illness |
| Pregnant/Breastfeeding Women | Much higher nutrient needs |
Who Is Most Likely to Develop Obesity?
Obesity, or having too much body fat, can happen to anyone but certain factors or situations make people more likely to develop this condition.
People with Certain Genes
Your genes can make you more likely to gain weight, but they are not the only reason. Some people may have genes that cause them to feel hungrier, store more fat, or have a slower metabolism, especially if family members are overweight. But lifestyle choices like diet and exercise still have a big impact.
People Who Are Inactive
With more jobs and hobbies happening while sitting, many people move less than before. Using cars, computers, and watching television all add up to less physical activity. When you use less energy than you take in through food, weight gain is likely to happen.
Low-Income Groups
In richer countries, being poor often means higher obesity. When people can’t afford healthy foods, they buy cheaper, processed options high in sugar and fats. These foods fill people up but don’t give the body needed vitamins and minerals, leading to unhealthy weight gain and poor health.
Certain Ethnic or Racial Groups
Some groups have higher obesity rates. This comes from a mix of genetics, traditions around food, lack of access to health care, and how easy it is to get good food. Culture and income can both play a big part.
People Taking Some Medications
Medications like some antidepressants, steroids, and drugs for mental health or diabetes can make people gain weight. These drugs can increase hunger, slow metabolism, or cause the body to hold on to more water or fat. People on these medications might need extra help to keep a healthy weight.
| Obesity Risk Factor | Example |
|---|---|
| Genetics | Family history of obesity |
| Lack of physical activity | Sitting jobs, little exercise |
| Poverty | Relying on cheap, unhealthy foods |
| Ethnic group | Higher rates in certain groups |
| Medication use | Taking steroids or some antidepressants |
Common Questions About Who Can Be Affected by Malnutrition and Obesity
Can Children Be Malnourished and Obese at the Same Time?
Yes, and this is now called the “double burden of malnutrition.” A child can be overweight or obese but still miss important vitamins and minerals if their food is mostly unhealthy, high-calorie options like sweets and fast food. This means their body is getting a lot of energy but not things like vitamin D, B vitamins, or folic acid. Even if a child looks well-fed, they might still have poor nutrition inside their body.
Who Needs Extra Nutrition Checks?
- Patients in hospitals (20-60% may be malnourished)
- People having or planning weight-loss surgery (they often have low iron, calcium, folic acid, vitamin D, or B12 even before the operation)
- People with chronic illnesses
- Pregnant and breastfeeding women
- Older adults
For all these groups, doctors can’t just look at weight. Many who are overweight still lack important nutrients, so checking what they eat and their nutrient levels is important-not just their BMI.
Do Developed and Developing Countries Face the Same Problems?
Both rich and poor countries face malnutrition, but the causes and common problems are not always the same. In poorer countries, undernutrition-like stunted growth and wasting (low weight for height)-is still a huge problem, largely because people don’t have enough to eat or can’t get healthy foods. But obesity is increasing there too, so now both problems can happen together. In wealthier places, people usually get enough food, but unhealthy diets and less movement mean more people are obese and still missing key nutrients. So, malnutrition looks different in each place, and the best actions depend on what the main problem is in that country or community.
