sugar in wooden bowl on dark surface

Why Do You Get So Tired After Eating Sugar?

You know what I mean right? Having a sweet tooth is hard to resist when faced with a cake, cookie or ice cream. With every bite you savor the joy it brings. However afterward—whether it's minutes or hours—you suddenly feel drained, irritable and even develop a pounding headache. All you crave is to snuggle up on the couch for a nap.

Why does this happen? Why does sugar leave us feeling so fatigued? What can we do to prevent it?

The Science Behind Sugar Crash

Consuming sugar can result in feelings of fatigue due to its impact on your blood sugar levels and brain chemistry. When you consume sugar your blood sugar levels experience an increase followed by a decline leading to symptoms, like tiredness, mood fluctuations and headaches. This phenomenon is commonly referred to as a "sugar crash" or post meal hyperglycemia.

Consuming sugar has the potential to inhibit the production of orexin, a substance for promoting wakefulness and vitality. It is worth noting that individuals may exhibit varying sensitivities to sugar leading to levels of beta endorphin and serotonin in the brain. Such imbalances can have an impact on one's mood and energy levels.

My Personal Experience with Sugar Crash

I used to have a tooth. Sweets were a part of my meals even making appearances, at breakfast, lunch and dinner. I used to believe that sugar was my source of energy and happiness. However I eventually realized that sugar was actually having an impact on me.

It turned out that consuming sugar made me feel bad overall. I constantly felt tired after getting eight hours of sleep. My mood would swing unexpectedly. I became easily irritated. Concentrating and remembering things became more difficult for me.

That's when I made the decision to cut back on sugar and observe the changes it brought about in my life. You know what? It made such a huge difference! My energy levels soared, so did my focus. My overall happiness improved noticeably. As an added bonus I managed to shed some weight and noticed an improvement in the quality of my skin.

Now don't get me wrong, I still have some sweets from time to time. However the frequency and quantity has significantly decreased compared to before. I always strive to maintain a balance by incorporating foods into my diet.

How to Prevent Sugar Crash

sugar lies on the black background

If you want to avoid feeling tired after eating sugar, here are some tips that work for me:

  • Make sure to have a rounded diet that consists of foods, in fiber like whole grains, fruits and vegetables. Fiber plays a role in regulating the speed at which sugar is absorbed into your bloodstream thereby keeping your blood sugar levels steady.
  • Avoid sugary foods and processed simple carbohydrates, such as white bread or white pasta, especially on an empty stomach. These foods can spike your blood sugar levels quickly and cause a crash later.
  • When drinking alcohol, eat food with it. Alcohol can lower your blood sugar levels and make you feel tired.
  • Eat several small meals and snacks about three hours apart throughout the day. This helps keep your metabolism active and your blood sugar levels steady.
  • Exercise on a regular basis. Exercise helps burn off excess sugar in your blood and improves your insulin sensitivity.


Sugar can be quite tempting. Consuming large amounts or having it at inappropriate times can leave you feeling fatigued. By adhering to these guidelines you can indulge in treats, without experiencing drowsiness. 

James Freeman


Liam Marshall, the friendly fitness coach, has spent 14 years sharing his love for sports and fitness. With degrees in sports science, he crafts workouts that fit like your favorite jeans. Beyond the gym, he organizes sports clinics and tech-savvy fitness apps that motivate people worldwide. He's all about making fitness doable for everyone, and it's not just about bodies – it's boosting confidence. In 2019, he scored the "Virginia Fitness Coach of the Year" award. Outside the fitness world, he loves family time and hikes in Shenandoah National Park. Liam's journey from a small-town fitness fan to a big-time coach is all about passion, inspiring people to see fitness as a body-and-mind thing. Catch him on Instagram to stay in the loop!