12 Signs You're Not Eating Enough

Common causes include dieting and over-exercising.
Constantly feeling cold is a telltale sign.
Constantly feeling cold is a telltale sign.
boram kim / Unsplash

Whether it's because of stress, illness, fad dieting, a traumatic event or busy schedule, for many people it can be easy to skip meals and undereat. And just like overeating, undereating has a negative impact on our physical and mental health.

Aside from the obvious symptom of weight loss, there are many signs indicating you're not eating enough. To find out what they are, HuffPost Australia spoke to two health experts.

Common causes of undereating

"Not eating enough can be caused by restricting energy intake, exercising and not meeting energy requirements, or a combination of both," accredited practising dietitian and performance dietitian Jessica Spendlove told HuffPost Australia.

"This can happen deliberately, such as someone trying to lose weight and reducing their energy intake, or indirectly by someone increasing their exercise and not adjusting their intake to match their requirements."


Trends (and misinformation) around diets and nutritional advice can also account for undereating, nutritionist Steph Lowe of The Natural Nutritionist explained.

"Absolutely. With the abundance of fad diets and calorie restriction claims being made and marketed to us on a daily basis, not eating enough is not unheard of and will cause more harm than good," Lowe said.

Common causes of undereating

  • Dieting or restricting calories
  • Over-exercising
  • Not adjusting energy intake to match exercise
  • A combination of the above.

"Undereating can also occur when someone consumes a diet rich in nutrient-dense but low-energy foods, such as lots of salads and vegetables," Spendlove said.

"While getting enough vegetables if of course important for overall health, predominantly eating only these foods can result in someone not consuming enough energy."

Excessive exercise and not eating enough to fuel your exercise can have negative effects on your health.
Excessive exercise and not eating enough to fuel your exercise can have negative effects on your health.
Nikada via Getty Images

Signs you're not eating enough

There are a number of signs which appear when someone is not eating enough. Some present more immediately than others, while others take weeks or months.

"Not eating enough can wreak havoc on your hormones, slow down your metabolism, lead to unnecessary anxiety and is considered a form of stress on the body which can actually cause the body to hold onto weight rather than lose," Lowe told HuffPost Australia.

"Weight loss, lack of energy and fatigue are the most common signs, as well as frequent cravings and irritability, which can indicate hormone and blood sugar imbalance.

"Other symptoms such as hair loss, paleness, brittle nails or dizziness can indicate a nutrient deficiency and a blood test should be prioritised."

Signs of undereating include:

  • Low energy levels and constantly feeling tired or exhausted
  • Regularly constipated
  • Constantly hungry
  • Moody and irritated easily
  • Poor mental concentration
  • Dizziness
  • Loss of period or normal menstrual function
  • Inability to get pregnant
  • Constantly thirsty
  • Constantly feeling cold
  • Hair loss and brittle nails
  • Pale complexion

"Your body is very intelligent and will give you all the signs of a thriving body when eating the right foods versus a depleted body," Lowe explained.

"For example, nourishing the body with real food allows you to feel energised, think clearly, feel satisfied with no cravings. In comparison, if you experience frequent heart burn, feel constantly fatigued, experience the 'hangries' on a daily basis and are gaining or losing weight, it's likely your intake is not sufficient."

Always feeling cold is a common sign of undereating.
Always feeling cold is a common sign of undereating.
flyparade via Getty Images

What to do if you're undereating

If you're experiencing any of the above signs, it's important to see a healthcare professional such as a GP.

"Speak to a professional in the field such as a nutritionist or dietitian, and undertake a blood test to ensure you are not suffering from any underlying nutritional deficiencies," Lowe said.

If you're an athlete or train regularly and are struggling to balance your diet, Spendlove recommends seeing an accredited practising dietitian or sports dietitian.

"Increasing intake through food is ideal, but in some instances supplementation might be required.

"If someone is concerned about their relationship with food they may want to consider working with a psychologist."

Constantly feeling thirsty is another sign.
Constantly feeling thirsty is another sign.
Getty Images

From a nutritional perspective, to help you increase your energy intake, Spendlove and Lowe recommending focusing on healthy fats.

"Foods which are high in good fats are both nutrient-dense and high in energy. These meal and snacks ideas are great for increasing energy intake, as every gram of fat is double the energy value compared to protein and carbohydrate," Spendlove said.

Healthy calorie-dense meals and snacks include:

  • Sourdough toast with avocado and feta
  • Smoothies with nuts, nut butter or avocado
  • Handful of nuts added to a meal, snack or smoothie
  • Rice cakes or whole grain crackers with avocado and salmon, or cream cheese and salmon
  • Rye toast with peanut butter, honey and banana
  • Greek yoghurt with natural granola and fruit

If you need help in a crisis, call Lifeline on 13 11 14. For further information about depression contact beyondblue on 1300 224 636. For specific information or support relating to eating disorders call Butterfly Foundation on 1800 ED HOPE or talk to your GP, local health professional or someone you trust.