5 signs you’re not eating enough

Under eating can happen for many reasons.

It might be because you’re on a diet that avoids foods it deems bad, unhealthy, or too high in calories.

It might be that you believe eating an adequate amount of food is overeating, so you try to cut back.

It’s really common with the clients we work with to not know that they’re undereating.

Two slices of two with strawberry jam on top. This is on a board, being eaten by someone with anorexia.

This blog will give you an insight into 5 signs that you’re not eating.

We think a few of them will shock you.

Let’s jump in…

    1. You’re cold

Do you constantly need to layer up because you’re cold?

For some, being hungry is signalled by feeling cold. Especially in cases of extreme hunger, where your body hasn’t had enough food in a significant time (e.g. more than four hours)

Your body can regulate its own temperature by thermoregulation. That’s what makes you sweat after exercise or shivering in cold weather – like an internal thermostat.

Like most of our body’s functions, it needs glucose (aka sugar) to work. You don’t have enough glucose to keep this process running properly when you don’t eat enough.

When you’re not eating enough, your body goes into a little bit of starvation mode. In order to keep you running on lower energy it slows down your metabolism and lowers your body temperature.

Think of it as you turning your heating down if you have less money to pay your heating bill.

Studies have shown that people who under-eat through dieting actually have a lower body temperature than those who don’t.

Aka, the more you diet, the slower your metabolism actually becomes!

How to tell if you’re feeling cold because of hunger:

    • Increase your intake and see if your body temperature starts to go up
    • Note if after you eat you experience feeling warm and drowsy.
    • Notice if when you’re wearing extra layers and applying external heat if you still feel cold

2. Your period is gone or it’s irregular

You might have heard of hypothalamic amenorrhea. It’s the technical term for losing your period.

There’s a term called ‘ovarian set point’ which means different women require different amounts of energy to have a period.

Periods can also be affected by stress, changes in weight, contraception, medication use, age, sleep and even travelling across time zones. 

3. You have a really low mood

This can be depression and feeling low or being easily irritated. Hangry is a controversial term but is often used when you snap at those around you when you’ve under-eaten.

The nutrients from our food affect the brain, especially the emotional centre.

Serotonin, sometimes known as the happy hormone, is drastically reduced as it is synthesised from our diet.

People suffering from anorexia have been found to have significantly lower levels of serotonin. Low levels have been associated with depression and low mood.

There’s a strong link between eating disorders and low mood; whether you’re restricting, purging or binging.

Between 50 and 75% of those struggling with an eating disorder experience symptoms of depression.

Notice when you are experiencing low mood or irritability – is there a crossover between these and periods of not eating enough?

How to improve low mood caused by undereating:

    • Re-introduce food groups you may have been cutting out
    • Work with a professional if low mood persists (like our nutritionists, dietitians, and therapists at Ease Nutrition Therapy)
    • Tap into your social network

4. You’re constantly thinking about food

Food obsession is a sign that your body is being deprived of vital nutrients.

Restricting is technically semi-starvation for your body. Have you heard of the Minnesota Starvation Experiment? It showed that undereating to the point causes obsessive thoughts about food, which only cease when food intake is increased (this can take months!)

It’s not just physical restriction that has an income. Mental restriction leads to food obsession too.

5. You’re having digestive issues

Undereating slows down your metabolism. It can also make food move more slowly through your digestive tract.

This makes you feel fuller quicker, bloated, or have pain when eating. It’s super common to experience gut problems when you have disordered eating – every 99 in 100 people will have problems with their digestion!

Problems with digestion include constipation, diarrhoea, bloating, cramping, pain in the abdomen, acid reflux, and feeling full quickly.

Restricting and digestive problems

There are various ways that not eating enough impacts digestion and gut health.

This includes:

    • Electrolyte imbalances – electrolytes are used in muscle and nerve function. If you experience digestive issues that can lead to constipation or diarrhoea it may affect your electrolytes.
    • Lack of gut diversity – The amount of ‘good bacteria’ in your gut will decrease. Good bacteria in your gut need lots of diversity to thrive.
    • Skipping meals doesn’t stop your stomach from creating stomach acid and gas. Bloating then happens because you have nothing to digest.
    • Lazy Bowel Syndrome – also known as sluggish bowel or slow gut. This is when your bowel movements are slow and sometimes painful, often with constipation. This happens because bowel-related reflexes become weaker and digestion slows down.
    • Heartburn or reflux – undereating can cause stomach acid to aggravate your stomach.  This is because your body primes itself for food every few hours, and stomach acid can overflow when no food is eaten.
    • Social effects – if you’re constantly bloated or uncomfortably full it can affect your socialising.


What to do next

We hope that this list has helped shine some light on what you might be experiencing. Know you’re not alone – many people wonder why they’re experiencing the symptoms they are before realising they’re undereating. We’ve supported 100s to overcome disordered eating and live a full life.

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