What To Know about Malnutrition

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dietitian explaining nutrition facts on laptop to person while sitting on a wooden table with bowls of different foods

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Malnutrition (the lack of nutrition) can occur when your body doesn't get the right amount of nutrients it needs to function. Malnutrition can lead to problems like unintended weight loss, fatigue, and slower growth.

Not eating enough food, not having access to proper nutritious foods, living with an eating disorder, or having a health condition that affects how your body absorbs nutrients are the primary reasons why malnutrition can happen.

Types of Malnutrition

Malnutrition can be categorized based on causes, severity, and presentation. Understanding these distinctions helps healthcare providers determine the best treatment approach and management strategies.

Stunting in Children Under Five

Stunting is a form of growth failure that develops over time in children under 5 years due to chronic undernutrition and lack of access to sufficient food and healthcare. The height-for-age index can determine whether a child is experiencing stunted growth. This type of malnutrition can lead to cognitive impairments such as delayed motor skills, poor brain function, and low academic performance.

Wasting in Children Under Five

Wasting refers to a child being significantly underweight for their height, often resulting from acute food shortages or illness. Also known as acute malnutrition, wasting occurs rapidly and is measured by the weight-for-height index or mid-upper arm circumference (MUAC). It can be moderate or severe and increase the risk of premature mortality in children.

Protein-Energy Malnutrition (PEM)

Protein-energy malnutrition is a type of malnutrition that results from a lack of calories and protein. PEM can occur due to food insecurity, but it's also very common in those with cancer, end-stage renal disease receiving dialysis, and other chronic illnesses.

PEM can manifest in two ways: marasmus (which causes severe weight loss) and kwashiorkor (which causes edema and fatty liver).

Micronutrient Deficiency

Micronutrient deficiency occurs when the body doesn't get enough essential vitamins or minerals. Not eating a wide variety of foods or being unable to absorb nutrients properly can lead to this deficiency.

Common deficiencies include iron, zinc, iodine, vitamin D, vitamin A, or vitamin C—all of which can lead to fatigue, muscle weakness, or a weakened immune system. Eating a balanced diet with various fruits, vegetables, and proteins can help prevent micronutrient deficiencies.

Overnutrition

This type of malnutrition actually occurs when you consume too many nutrients, particularly fats, sugars, and calories. Overnutrition can increase your risk of health conditions like obesity, heart disease, type 2 diabetes, stroke, and certain cancers. Eating a balanced diet and getting support from a dietitian can help you find an eating plan that meets your body's needs.

Secondary Malnutrition

Secondary malnutrition happens when an underlying health condition (such as gastrointestinal disease, liver disease, or infection) prevents the body from properly absorbing or using nutrients. It can occur even if you're eating a balanced diet. When secondary malnutrition occurs, it may also cause nausea, vomiting, or poor appetite.

Malnutrition Symptoms 

Malnutrition can cause a wide range of symptoms and affect different parts of your body, depending on the severity and type of nutrient deficiency you're experiencing. Warning signs of malnutrition include:

  • Fatigue and weakness
  • Shortness of breath
  • Dizziness
  • Muscle weakness
  • Hair loss
  • Brittle nails
  • Poor wound healing
  • Unexpected weight loss
  • Frequent infections
  • Swollen abdomen and legs

Why Does It Happen?

Malnutrition occurs when the body doesn't receive the right balance of nutrients needed to maintain health and function. Several factors can raise your risk of experiencing malnutrition. These include:

  • Age: Being a child under the age of 5 years or being an older adult
  • Underlying conditions: Living with conditions like Crohn's disease, celiac disease, or chronic infections
  • Poverty: Experiencing limited access to nutritious and affordable foods
  • Food insecurity: Not having availability or access to sufficient and diverse foods, such as living in a food desert
  • Lack of access to care: Having inadequate medical care that can help address nutrition concerns and other health conditions
  • Poor eating plan: Eating foods that lack essential nutrients that your body needs to function
  • Restrictive diets: Eliminating key food groups and nutrients from your meal plan

The Diagnostic Process

To diagnose malnutrition, healthcare providers begin by asking about your medical history and reviewing your diet. They also check for physical signs of nutrient deficiencies and use various tests to confirm if you have malnutrition or to rule out other health conditions.

Common diagnostic tests may include:

  • Blood test: Checks for anemia and vitamin deficiencies
  • Body mass index (BMI): Measures your height and weight
  • Mid-upper arm circumference (MUAC): Calculates the circumference of your arm to assess malnutrition
  • Skinfold thickness measurement: Assesses the thickness of skin folds to determine body fat and overall nutritional status
  • Serum albumin test: Detects the level of albumin (a protein) in your blood to assess protein status and potential malnutrition
  • CT or MRI scan: Uses imaging tests to take detailed pictures of the internal organs to diagnose any digestive disorders that may be contributing to malnutrition

Registered dietitians might perform a nutrition-focused physical exam (NFPE) to identify and assess the degree of malnutrition. They'll look at things like muscle and subcutaneous fat wasting, micronutrient deficiencies (e.g., hair loss, brittle nails), and functional capacity.

Treatment Options

The primary goal of treating malnutrition is to restore and maintain proper nutritional balance, ensuring the body receives the essential nutrients it needs to function optimally. This involves correcting any deficiencies and addressing underlying causes.

Adjustments to diet are crucial for managing malnutrition. This might include increasing the intake of specific nutrients or calories through a well-balanced diet or eating specialized meal plans. For severe cases, healthcare providers may recommend fortified foods or nutritional supplements.

When underlying medical conditions cause malnutrition, it's crucial to address these conditions to manage malnutrition effectively. For example, if digestive disorders such as Crohn's disease impair nutrient absorption, medications can help improve nutritional status.

How To Prevent Malnutrition 

Take proactive steps that address your dietary needs and underlying health conditions to prevent malnutrition. Here are some effective strategies to lower your risk of malnutrition:

  • Review medication effects: If you're taking medications that reduce your appetite, talk to your healthcare provider about how to ensure you're still receiving the nutrients you need.
  • Consume a balanced diet: Ensure your diet includes a variety of nutrient-rich foods. Aim for foods high in potassium, calcium, vitamin D, and vitamin B12. Include fruits, vegetables, whole grains, dairy products, and lean proteins in your meals. Fortified foods can also help meet your nutritional needs.
  • Consult a nutrition expert: A registered dietitian can help tailor a diet plan that meets your needs to prevent malnutrition and support your overall dietary needs.
  • Stay active: Engage in regular physical activity that you enjoy, as this helps maintain or build muscle mass.

Complications

Untreated malnutrition can lead to several serious complications and symptoms. These include:

  • Heart palpitations
  • Fainting
  • Chest pain
  • Constipation
  • Diarrhea
  • Abdominal pain
  • Difficulty breathing
  • Sarcopenia (loss of muscle mass)
  • Osteopenia (loss of bone density)

A Quick Review

Malnutrition occurs when your body lacks essential nutrients, leading to symptoms like unexpected weight loss, fatigue, and stunted growth. Lack of access to nutritious foods, living with health conditions like Crohn's disease, eating a restrictive diet, and being under the age of five are the most common risk factors of malnutrition.

Addressing vitamin deficiencies and eating a balanced meal plan can help improve malnutrition and nutrient absorption.

Frequently Asked Questions

  • What should you eat if you are malnourished?

    If you're malnourished, focus on eating a balanced diet rich in diverse, nutrient-dense foods such as fruits, vegetables, lean proteins, whole grains, and dairy products to address deficiencies.

  • How long does malnutrition take to fix?

    The time it takes to address malnutrition varies depending on its severity, underlying causes, and the effectiveness of treatment. Improvements can often be seen within a few weeks to several months.

  • What organs does malnutrition affect?

    Malnutrition can affect every organ system, including the heart, lungs, kidneys, and digestive system, potentially leading to severe dysfunction in these areas.

Edited by
Sukhman Rekhi
Sukhman Rekhi

Sukhman is a former editor at Health.

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19 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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