Does Calorie Deficit Make You Tired?

Last Updated:

We may earn commissions for purchases made through links on our site. Learn more on our about us page.

Old woman sleeping on a couch - Does Calorie Deficit Make You Tired?

When it comes to losing weight, many people have the same advice: eat less and move more. And whilst this is generally sound advice, what people often leave out is that this creates a calorie deficit that may leave you feeling tired. 

So what is a calorie deficit? A calorie deficit occurs when you’re burning off more calories than you consume in a day. 

And whilst this does indeed help you lose weight, it can leave you feeling tired, which can have a negative impact on your day-to-day life. It doesn’t have to, though: read on to find out how you can combat calorie deficit fatigue!


Can Calorie Deficit Make You Tired?

Calorie-deficit fatigue is a common side effect when partaking in a diet that requires you to limit the amount of food that you eat. 

This is because our bodies require energy for all biological functions like pumping blood and breathing, as well as for any physical activity that we may do. 

And this energy comes from food, so by not eating enough calories, you will find that you start to get tired quicker than usual. 


How Do You Avoid Feeling Tired Because of a Calorie Deficit?

Although feeling tired is naturally going to occur if you’re on a calorie deficit, there are things that you can do to try and avoid this: 


  • Increase the number of carbohydrates that you’re eating. The nutrients from carbohydrates are the body’s main energy source, so a diet that does not include carbohydrates will lead to an increase in fatigue. 
  • Don’t drink energy drinks. Whilst reaching for an energy drink when you’re feeling sluggish may seem like a good idea, all it will result in is an energy spike, followed by a crash that will make you feel worse than before. 
  • Instead of eating three large meals a day, try to eat small and frequent meals to give your body a steady supply of nutrients. This type of eating is what many Doctors do to get through long shifts; a piece of fruit can refuel your brain and help prevent sluggishness. 
  • Stay hydrated! Water is incredibly important to avoid tiredness as it transports nutrients to cells and removes waste products. 


Things to Eat If You Want to Avoid Feeling Tired Because of a Calorie Deficit?

Some foods are better at boosting energy than others, and these are the types of foods that should feature heavily in your diet and eating plan: 


  • Unprocessed foods 
  • Fruits and vegetables 
  • Lean proteins 
  • Carbohydrates 
  • Nuts and seeds
  • Vitamins and supplements 
  • Oats
  • Chia seeds


It is also important to keep hydrated by drinking water. Doctors suggest that you should be drinking at least 8 cups of water a day to stay hydrated! 

Does Eating Certain Food Causes You to Feel Tired Because of a Calorie Deficit?

Just because food creates energy does not mean that you should be eating anything whilst you’re in a calorie deficit. Some food and drink will do more harm than good and leave you feeling even more tired.

Avoid eating foods with a high glycemic index, which is how we rank food according to how it affects blood glucose levels. Foods with a low glycemic index digest slower, don’t spike your blood sugar and keep you energized. 

However, food with a high glycemic index will make you feel tired as they induce a steep rise in your blood sugar, which gives you a burst of energy that will leave you crashing afterward. Foods like this include sweets, soda, and fruit juice. 

Another type of food to avoid is food that is hard to digest. 

The harder food is to digest, the more tired you will feel as you will have to work harder to increase the blood flow to your stomach in order to digest properly. This includes foods high in fat like red meat and fried food. 


When Should You Eat if You Want to Stop Feeling Tired Because of a Calorie Deficit?

The key to avoiding fatigue during a calorie deficit diet is to not eat three meals a day and instead eat smaller meals at three or four-hour intervals or when you begin to get hungry. 

In doing so, you will feel more energized as your body will receive a steady supply of nutrients needed to get through the day. 

Of course, this approach only works if you’re eating the correct food. Eating anything that is high in sugar won’t do much in the way of increasing your energy, but eating a piece of fruit or some nuts will! 


Final Thoughts on Calorie Deficit Making You Tired

And there you have it, everything you need to know about calorie deficits and the tiredness they can cause! However, if you stick with a carbohydrate-heavy eating plan, stay hydrated and cut out sugary foods, you can bypass this tiredness! 

Of course, this type of diet is quite extreme, so it may be a good idea to consult with a dietitian or a healthcare professional before undertaking such a lifestyle change. 


Leave a Reply