Health & Wellness

Understanding the 12 Side Effects of Not Eating Enough

Not eating enough can lead to various side effects on the overall health and well-being of individuals. We aim to provide detailed guidance on the side effects of not eating enough. We will also discuss the reasons behind undereating.

What is Under-Eating?

Under-eating or not eating enough can result from many reasons such as due to calorie restriction people follow for weight loss, extreme food restraint associated with eating disorders like anorexia nervosa, unhealthy eating habits, etc. This causes starvation to which the brain response is physical and emotional damage.

Reasons for Undereating:

There are many reasons behind the under-eating of individuals, such as: including

  • Intentional dietary restrictions for weight loss
  • Eating disorders
  • High levels of physical activity and less food intake
  • Stress among individuals
  • The financial constraints.

It’s crucial to understand the real reasons behind undereating to address it.

Side Effects of Not eating Enough: 12 Symptoms:

Not eating enough leads to various malnutrition consequences which are:

  1. Research has proven a relationship between anxiety and insufficient food intake. When the body lacks essential nutrients, it can negatively impact mental health. It results in prolonged periods of anxiety and depression.
  2. Malnutrition can lead to underweight conditions. It causes various health complications such as malnutrition, infertility, and weakened immune system.
  3. Inadequate food consumption causes slower digestion which leads to constipation.  It is characterized by infrequent bowel movements and difficulty passing stool.
  4. Not eating enough can also hinder the weight loss efforts of an individual. The body’s metabolism slows down to conserve energy.
  5. Fatigue is caused by insufficient calorie intake. The body deprives essential fuel for basic functions. This leads to fatigue and low energy levels.
  6. Lack of calories decreases body temperature which causes individuals to feel cold more often.
  7. One starts to feel frequent hunger and food cravings as the body signals the need for nourishment.
  8. Nutrient deficiencies can manifest in hair loss. It is due to inadequate food intake as the body prioritizes vital functions over hair growth.
  9. It also causes hormonal imbalances like infertility. It results from calorie deficiency. It can impact reproductive health, and make it difficult to conceive.
  10. Caloric restriction is linked to mood swings and irritability that affect overall emotional well-being.
  11. It disrupts sleep patterns and leads to sleep interruptions and difficulty falling asleep.
  12. The immune system weakens due to a lack of proper nutrients. It makes individuals more susceptible to infections and illnesses.

The Brain’s Response to Starvation:

The brain’s response to starvation/ lack of nutrition in the body is a complex adaptive process aimed at preserving vital functions and resources within the body. This triggers a range of physical sensations and emotional effects:

  • The brain initiates various adaptive responses during starvation periods to conserve energy and essential nutrients.
  • Starvation causes some physical symptoms such as chilliness, restlessness, slowed digestion, and digestive discomfort.
  • It also impacts mood and cognitive function which leads to changes in emotional well-being and mental clarity.


Q1. What happens to the body when you don’t eat enough?

It can lead to various health issues:
weight loss, 
mood swings, and 
weakened immune function.

Q2. What happens if you don’t get enough to eat?

It results in malnutrition, nutrient deficiencies, hormonal imbalances, and an increased risk of health complications in individuals not getting enough to eat.

Q3. What happens if a runner doesn’t eat enough?

Inadequate food intake can impair athletic performance. It can cause delay recovery, and increase the risk of injuries among runners. It happens because they need more energy which can be obtained by more food intake.


Not eating enough can have profound consequences on your physical, mental, and emotional health. It’s essential to recognize the deprivation effects of insufficient eating. You should address the underlying reasons to promote overall well-being. Consult healthcare professionals and adopt balanced eating habits to maintain a healthy relationship with food. It can nourish your body effectively.

Medical Disclaimer: We only provide information for educational purposes. Do not consider it a medical advice for you. In case of need, consult the healthcare professional for proper diagnosis and treatment.

Kelly Han

Dr. Kelly Han is a seasoned medical professional with a passion for holistic wellness and integrative health. Based in San Francisco, her expertise spans across various domains of health, from fitness and skincare to oral health and weight management. Understanding the intricate connections between different aspects of health, Dr. Han believes in a comprehensive approach. Whether it's the latest skincare regimen, effective weight loss strategies, or understanding hormonal imbalances, she's dedicated to providing readers with evidence-based advice and actionable insights on a wide array of health topics. Through her articles, Dr. Han aims to empower individuals to take charge of their well-being, offering them the knowledge and tools they need to lead healthier, more vibrant lives. Join her in exploring the multifaceted world of health, beauty, and wellness.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button