Symptoms of Not Eating

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Symptoms of not eating vary based on the amount of time since a person last ate, age, and chronic conditions a person may have. Some of the initial symptoms are a result of the body not having enough sugar and include shakiness, irritability, nausea, and more. In most cases, eating resolves these symptoms.

If a person continues not to eat, they can have slurred speech, confusion, syncope (fainting), or seizures. Prolonged lack of nutrition can lead to severe weight loss, fatigue, depression, and stomach issues. 

Symptoms of Malnutrition

Verywell / Ellen Linder

Frequent Symptoms 

The most common symptoms of not eating include low blood sugar, low energy levels, and malnutrition.

Decreased Blood Sugar

When a person doesn’t eat enough, their body doesn’t get the proper amount of glucose (blood sugar), and their blood sugar drops

Some of the initial symptoms of decreased blood sugar include:

  • Extreme hunger
  • Difficulty concentrating
  • Nausea
  • Dizziness 
  • Shaking or feeling weak
  • Clamminess (pale, sweating, chills)
  • Fast heart rate (tachycardia)
  • Irritability or anxiety
  • Problems with coordination
  • Headaches

Blood Sugar Crash

For most people with low blood sugar levels, eating will resolve their symptoms. If the person does not eat enough, the body will continue to experience a blood sugar crash.

As blood sugar continues to drop, symptoms get more serious and include:

  • Blurred vision
  • Slurred speech
  • Confusion
  • Fainting
  • Sleepiness
  • Tingling or numbness in the lips, tongue, or cheeks
  • Nightmares or crying out during sleep
  • Seizures

Low Energy Level

The calories we get from food provide energy for our bodies to function. One of the most common dangers of not eating enough calories over an extended period is low energy levels. If you have been feeling exhausted, regardless of how much sleep you are getting, it may be a symptom of not getting enough calories or eating the right type of food.  

Symptoms That Co-Occur With Low Energy

In addition to experiencing low energy levels due to not eating, you may also experience:

  • Dehydration
  • Feeling cold
  • Weight loss
  • Fatigue
  • Problems sleeping
  • Stomach pain or bloating
  • Gastrointestinal issues such as constipation or diarrhea
  • Depression

Malnutrition: Decreased Nutrients and Minerals

As poor intake continues and the body does not receive enough nutrition, multiple functions are affected. The body continues to become deficient in calories as well as carbohydrates, protein, or fats. It may not be receiving critical minerals and nutrients such as calcium, magnesium, vitamin C, and protein. 

Over time, symptoms of malnutrition start to occur, and they include:

  • Thinning hair
  • Pale complexion
  • Decreased muscle tone and strength
  • Weakened immune system (frequent infections)
  • Disruption or stopping of the menstrual cycle
  • Rashes and bruising easily

Rare Symptoms

Prolonged disruption in nutrition causes the body to decline. A person may start experiencing long term symptoms of malnutrition such as:

  • Being very thin or emaciated
  • Brittle hair and nails
  • Glossitis (inflammation of the tongue)
  • Stomatitis (inflammation of the mouth)
  • Fine, downy body hair (called lanugo)
  • Dry or yellowish skin
  • Infertility (unable to get pregnant)
  • Slow wound healing
  • Prolonged bleeding from wounds
  • Bone thinning and fractures
  • Anemia (low iron levels)
  • Heart problems

Complications/Sub-Group Indications

Infants and Children

Infants and children have key differences in their metabolism that cause them to use up more protein, glucose, and lipids to maintain their baseline energy. This can cause them to show symptoms of not eating more quickly than adults.

Infants and children who are not getting enough to eat may be lethargic (not responsive), sleeping more than normal, and be fussy or irritable. 


Teens may have delayed growth or appear short in stature. They may also lack the usual symptoms of puberty due to disruptions in hormones from lack of glucose and calories.

Decreased caloric intake in children and teens may also include symptoms such as:

  • Fragile bones
  • Learning difficulties
  • Personality issues
  • Mood problems

Chronic Conditions

Those with certain chronic conditions may experience symptoms more rapidly or not compensate (go back to baseline) as quickly as an otherwise healthy person. The following are examples. However, this list is not all-inclusive. If you have a chronic illness, ask your doctor how not eating may affect your body differently. 


Not eating can be especially dangerous for people with diabetes because they take medications to lower their blood sugar. They need to check their blood sugar regularly and practice healthy eating habits to prevent blood sugar crashes. 


Those with cancer, especially those receiving chemotherapy, may experience a decreased appetite, gastrointestinal issues, and sores in their mouth. All of this can lead to not wanting to eat, weight loss, and malnutrition.

Malnutrition in Cancer Patients

The prevalence of malnutrition in cancer patients ranges from 20%-70%.

Sickle Cell Disease

Children and adults with sickle cell disease have a higher metabolic demand. This means they require more caloric (energy) intake and protein than otherwise healthy individuals to maintain normal growth, development, and muscle mass.

Poor nutrition can also lead to joint pain, infection, and anemia, resulting in a painful crisis and hospitalization for those with sickle cell disease. 

Gastrointestinal (GI) diseases 

Chronic illnesses such as Crohn’s, ulcerative colitis, or irritable bowel syndrome (IBS) can cause a lack of ability to absorb nutrients the body needs. People with gastrointestinal diseases may not have the reserve of sugar, fat, or nutrients that an otherwise healthy person would have. This can cause their symptoms to occur more rapidly.

When to See a Doctor

If you experience symptoms mentioned above that are not resolved by eating, be sure to talk to your doctor.

If you or a loved one are experiencing any of the following, seek emergency help immediately:

  • Vomiting or diarrhea that won’t stop
  • Persistent tachycardia (fast heart rate) or chest pain
  • Bleeding that won’t stop
  • Unresponsiveness (not waking up)
  • Trouble breathing
  • Slurred speech, or drooping on one side of the body
  • Persistent disorientation or confusion
  • Seizures
  • Injury to neck or spine (this may occur from fainting and falling)
  • Sudden, persistent, unusual, or bad headache
  • Sudden confusion
  • Unable to speak, see, walk, or move

A Word From Verywell 

Lack of nutrition may be a result of a person not eating a well-balanced diet, not getting enough to eat, or not eating at all. While not getting enough nutrition can be hazardous to your health, it’s rarely too late to start eating a healthy well-balanced diet. 

If you are worried that your child is not eating enough, consult with their pediatrician. These healthcare providers use charts to help them monitor your child’s growth and development. They watch for a rapid decrease in weight and slowing or stopping of expected height growth rates. 

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Verywell Health 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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