Do you wonder why you feel sluggish after eating your favorite fast food meal? Foods should make you feel energetic, but sometimes they do the opposite. It's likely to do with sugar and how your body processes it, affecting many functions. Why does sugar make you sleepy? Find out the biological reasons for this phenomenon and learn tips to prevent it.

Why Does Sugar Make You Sleepy?

There are five reasons glucose affects your daytime wakefulness.

1. It Increases Fatigue

People with diabetes are the most susceptible to fatigue problems after meals. It's called diabetes fatigue. However, it can also happen to healthy individuals.

Ingesting sweets can lead to a spike in glucose levels, to which the body responds by producing insulin that moderates these incoming chemicals. This hormone enters the bloodstream, collects the sugar and drops it on the cells for energy. If your body fails to generate enough insulin or has a problem using it effectively, the excess sugar in the blood can impact your fatigue level.

2. It Triggers Inflammation

Another factor why sugar makes you sleepy is inflammation — fatigue is one of the symptoms. Blame the food you ate if you feel less energized after stuffing your stomach.

Inflammation is the main catalyst for developing chronic diseases and a weakened immune system. In a study, researchers found that dietary sugars and mixed processed foods can aggravate inflammation by increasing biomarkers, and elevate the risk for non-communicable diseases like obesity and heart disease.

3. It Hurts the Gut

Poor gut health may manifest as physical fatigue, with reasons ultimately linking back to your diet. The gut microbiota is a collection of bacteria and other microorganisms that work together during digestion. The saying "You are what you eat" is true — the food you ingest can affect the balance and composition of the gut microbiota.

One study determined that a group of bacteria called Holdemania was associated with processed meat and consumption was linked to mental and physical fatigue. Hunks of ham, turkey and beef are loaded with preservatives, including seasonings and sugar, and are generally considered unhealthy. Moreover, they increase the risk of cancer, so it's best to avoid them to prevent feeling tired.

4. It’s Bad for Mental Health

You may have to ditch sugar because it deteriorates your mental health and causes mood disturbances. Consuming sugar-loaded foods can weaken your ability to cope with stress and increase your likelihood of depression and anxiety. Fatigue and stress are key predictors of these cognitive disorders, which explains why you may want to doze off after having a big slice of cake for dessert.

One study confirmed that excessive sugar intake can increase the risk of substance use disorder. This mental health problem triggers imbalances in brain chemicals and alters the reward system. What's worse is it can affect the health of unborn offspring in pregnant women and increase the babies' vulnerability to mental disorders.

5. It Blocks Hypocretin Activities

Why does sugar make you sleepy? It interrupts mental processes. An active, thinking brain is associated with wakefulness — sugar can block these activities, leading to mental inactivity and sleepiness.

The hypothalamus has the orexin or hypocretin system that influences the reward circuitry, glucose regulation and wakefulness. Its activity is moderated by several hormones, nutrients and chemicals, including sugar. An increase in glucose can restrict the movement of orexin neurons, leading to narcolepsy type 1. This condition is characterized by excessive daytime sleepiness and cataplexy or sudden episodes of muscular weakness. Those with narcolepsy type 1 tend to have the highest weight and eat for times more calories than usual when given unlimited snacks.

Making changes to your diet can help shift your energy levels. The next time you order lunch, snip out sugary options, like your favorite soft drinks or processed orange juice.

How to Prevent Daytime Sleepiness

The body needs sugar to function properly. The reason it's been associated with worsening health outcomes is overconsumption. Therefore, limiting your intake is key to a balanced diet. Here are some tips to reduce feeling lethargic after eating your meals.

Find Healthy Substitutes

Giving up your favorite dessert is hard, so opt for sweetener alternatives to prevent sugar spikes and crashes. An excellent option is coconut sugar because of its low glycemic index score, meaning consuming it has little effect on glucose levels. It lowers the risk of inflammation and fatigue.

If you're making cupcakes or cookies for your kids during a special occasion, replace brown or white sugar with coconut sugar for a healthier recipe. This way, you won't worry too much if they eat more than usual, and they won't feel guilty about it. You can also try stevia and maple syrup. The former is sweeter than sugar, so you only need less, whereas the latter doesn't cause jolts.

Eat Little but Often

Big meals can cause a sudden influx of sugar in your system. Eat an apple or a handful of nuts if you need some energy boost. It should restore your energy and keep you awake for the next few hours.

Get Out and Walk

It can improve your mood, support digestion and give you fresh air. If your workplace has a green space, walking for a few minutes can cure midday lethargy and increase your energy.

Get Enough Sleep at Night

In one study of 377 adolescents who were poor sleepers, 6.2% had excessive daytime sleepiness, which affected their school performance. Gaining quality shuteye decreases the risk of energy dip during noon time. It makes you awake throughout the day.

Take a Short Nap

If you feel sluggish, taking a quick nap is better than consuming caffeine. However, it shouldn't be longer than 30 minutes or it can disrupt your nighttime sleep. Napping is beneficial. It can increase your alertness to tackle your tasks.

Limit Sugar Intake

Now you understand why sugar makes you sleepy. You can limit your consumption to reduce inflammation, fatigue and adverse outcomes. Replacing brown or white sugar with coconut sugar, stevia and maple syrup can sidestep its roller coaster effect in your system. To get over post-meal tiredness, go out and do light exercise, nap and eat small amounts of food every few hours. Control lies in your hands to make a wiser decision.