Symptoms and Adverse Health Effects of Not Eating Enough

Sometimes, we do not eat enough to keep our bodies healthy. This can happen for a variety of reasons: an uptick in daily exercise (that’s not accompanied by an uptick in calorie intake), a low-calorie diet, stress, being too busy to eat proper meals, eating disorders, and more.

Not eating enough calories for your body’s needs can have devastating side effects. Though these side effects may be few and far between at first, as malnutrition sets in, you can deal with an array of adverse effects from not fueling your body.

How Many Calories Do I Need Per Day?
The right number of daily calories will vary from person to person. Calorie intake depends on your age, current health conditions, current weight, activity level, and more.

The general guidance provided by the Dietary Guidelines for Americans states that adult women need between 1,600 and 2,400 calories per day, while adult men need between 2,000 and 3,000 calories per day.

Symptoms of Not Eating Enough
If you are not getting enough calories to fuel your body and mind, you will experience plenty of signals. Most commonly, people who don’t eat enough will struggle with low blood sugar, malnutrition, and low energy levels.

Low Blood Sugar
When a person doesn’t have the correct amount of glucose (sugar) in their blood, they will experience hypoglycemia (low blood sugar). The symptoms of low blood sugar set in fast and are unpleasant.

Symptoms of low blood sugar include:

  • Extreme hunger
  • Dizziness
  • Sweaty palms
  • Agitation
  • Shaking and/or weakness
  • Headache
  • Nausea
  • Coordination issues

At this stage of hypoglycemia, eating a high-sugar snack like fruit, candy or juice will resolve the symptoms quickly. However, for those who do not eat after the initial symptoms start, hypoglycemia will continue to worsen, and new symptoms arise, such as:

  • Slurred speech
  • Confusion
  • Fainting
  • Sleepiness
  • Numbness or tingling in extremities
  • In extreme cases, seizures

If someone continually consumes too little food, they may start to face the adverse effects of malnutrition. Malnutrition is caused by a deficit in calories, and therefore a deficiency in essential carbohydrates, proteins, and vitamins.

The symptoms of malnutrition include:

  • Pale skin tone
  • Decreased muscle tone and/or strength
  • Easily bruising
  • Rashes and/or dry skin
  • Thinning hair
  • Fatigue
  • Weakened immune system (which will present as increased infections)

Allowing these symptoms to go unchecked is very dangerous. It can lead to more serious symptoms and conditions down the line, such as infertility, anemia, stomatitis, issues with the cardiovascular system, and more.

Eating a well-balanced diet with enough calories to sustain your body is crucial to good overall health. Ignoring the early signs of malnutrition is unwise. If you or someone you love is showing the symptoms of under-eating, it’s a good idea to see a registered dietitian who can set them on a nutritious diet plan tailored to their body and needs.

Not Eating: Signs, Symptoms, and Complications (
Calories: Recommended intake, burning calories, tips, and daily needs (
Know the 12 Symptoms of Not Eating Enough | New Health Advisor