Is feeling tired after eating a sign of diabetes?

Feeling sleepy after eating can be a sign of diabetes, but many people who don’t have diabetes also experience a slump in their energy levels following meals.

This usually has to do with your blood sugar responses to what you eat. But everyone is different in how they respond to food, and there is no one-size-fits-all approach to nutrition.

The ZOE at-home test can tell you the best foods for you, which could help you feel less tired after meals. You can take a free quiz to find out more about your unique responses to food.

Read on to learn more about why you may feel sleepy after eating.

Why do people with diabetes feel sleepy after eating?

Feeling tired at any time of the day, not just after eating, is a common issue for people living with diabetes. A recent study that involved over 42,000 people with either type 1 or type 2 diabetes found that roughly half of them reported feelings of exhaustion. 

While tiredness can be a regular occurrence if you have diabetes, exactly what causes it is not completely clear. 

Let’s explore what may contribute to tiredness or fatigue in diabetes. 

Blood sugar control

As we’ll see below, feeling sleepy after you eat is commonly due to changes in your blood sugar levels. 

However, for people with diabetes, the relationship between feeling fatigued and how well they control their blood sugar may not be straightforward. 

Some studies suggest that tiredness could be indirectly related to blood sugar levels in people with type 2 diabetes — but only when their diabetes is not under control.

Research is continuing, but a growing body of evidence relating to both type 1 and type 2 diabetes indicates that factors other than blood sugar control might be more directly related to fatigue. 


Chronic inflammation, a long-term response by your immune system, is thought to be at least partly responsible for the complications and symptoms of diabetes. 

In one small study, people with type 2 diabetes showed higher levels of inflammation and increased fatigue than those with type 1 diabetes.

Some evidence also suggests that regulating inflammatory responses in certain diseases including diabetes may help with tiredness after meals. 

Other possible causes

A number of lifestyle and other factors might contribute to people with diabetes feeling tired.

For those with type 1 diabetes, researchers suggest that possible links to fatigue include:

  • problems sleeping

  • lack of physical activity

  • depression 

  • pain 

For people with type 2 diabetes, scientists found multiple factors associated with fatigue, including:

Why anyone can feel sleepy after eating

Although certainly possible, feeling sleepy after eating doesn’t necessarily mean you have diabetes. 

Everyone’s blood sugar levels change following a meal. When these changes are significant, they can cause a drop in your energy levels.

As you eat, your body breaks down the carbohydrates in your food into glucose, which is a simple sugar. As the amount of sugar in your blood increases, your cells absorb it and either convert it into energy or store it for later.

As your cells take in sugar, the amount in your blood — your blood sugar level — goes down. Gradual increases and decreases in blood sugar are normal and nothing to be concerned about. However, not all foods affect your blood sugar the same way.

Complex carbohydrates, such as vegetables and whole grains, generally take longer for your body to break down. This allows glucose to be released into your blood more slowly, causing a gradual rise in blood sugar followed later by a gradual fall.

Simple carbohydrates, commonly found in fruit juice, sweets, baked goods, and ultra-processed foods, are broken down quickly. This leads to a large amount of glucose entering your blood at once. In other words, there is a higher spike in blood sugar, which can prompt a drastic fall, sometimes called a blood sugar “crash.”

These extreme spikes and crashes in blood sugar can be responsible for the slump in energy, difficulty concentrating, and other symptoms you may feel after a meal.

In one study, people who ate a diet that led to drastic blood sugar changes said they felt more tired on average than those who ate foods that gradually increased blood sugar. 

Other studies suggest that blood sugar changes may be associated with feeling tired as soon as 30 minutes after a meal. 

How to feel less tired after eating

Carbohydrates are an important part of a balanced diet. They are your body’s preferred source of energy, and many foods high in carbohydrates are great sources of important vitamins and minerals. 

But as we’ve seen, not all carbohydrates affect you in the same way. Choosing the right sources of carbohydrate may help you to feel less tired after eating.

If you’re looking to avoid drastic blood sugar spikes and crashes, focus on eating high-quality complex carbohydrates.

Good sources of high-quality complex carbohydrates include:

  • whole grains, like quinoa, oats, whole wheat, and brown rice

  • starchy vegetables

  • whole fruits

  • legumes, like beans, lentils, and peas

Limit foods high in simple carbohydrates, such as:

  • packaged cookies, crackers, and snacks

  • baked goods and pastries

  • sugary drinks, like soda, sweetened tea, and fruit juice 

At ZOE, we don’t believe in restrictive diets or cutting out any foods entirely. Some foods are simply better enjoyed as an occasional treat. And the foods that are the best for you are not necessarily the best for someone else.

Eating the right foods for you

When it comes to avoiding big blood sugar spikes and dips, there are some general guidelines you can follow.

However, to make sure you’re eating the best foods for you, it’s important to understand your body’s unique metabolism. And your blood sugar levels are not the only thing involved in shaping it.

Your gut microbiome is the name for the trillions of bacteria and other microorganisms that live in your gut. It plays an important part in your overall health and how your body responds to food.

When the “bad” bugs in your gut microbiome outnumber the “good,” it can have a negative effect on how your body manages energy.

At ZOE, we run the largest study of nutrition and the gut microbiome in the world, with over 15,000 participants so far. Our data show that there’s no one-size-fits-all approach to nutrition and that everyone responds differently to foods.

ZOE’s at-home test helps you to understand your body’s responses to different foods by analyzing your blood sugar, blood fat, and your gut microbiome.

Based on your results, we give you personalized recommendations of the best foods for you.

Our unpublished research found that 82% of people who closely followed their personalized ZOE nutrition program said they had more energy.


Feeling tired after eating could be a sign of diabetes, but it isn’t always. Around half of people who live with diabetes report feelings of exhaustion, not just after meals. 

The exact causes are unclear, but it may be to do with how well they control their blood sugar, inflammation, or other factors. 

Anyone can feel tired after a meal. It has to do with how your body responds to different foods.

Foods that can lead to spikes and crashes in blood sugar — such as sugary drinks, packaged snacks, and baked goods — could make you feel tired after eating. 

Vegetables and whole grains generally lead to more gradual blood sugar responses.

However, everyone responds differently to foods, so it’s important to understand your unique metabolism if you want to avoid feeling tired after eating. 

With ZOE’s at-home test, you can learn how your body responds to food and discover which are the best for you and your overall health.

Take a free quiz to learn more about what ZOE can do for you.


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Glucose control and fatigue in type 2 diabetes: the mediating roles of diabetes symptoms and distress. Journal of Advanced Nursing. (2015).

Prevalence and risk factors of fatigue in type 1 and type 2 diabetes: a systematic review and meta-analysis. Journal of Nursing Scholarship. (2021).

Role of the gut microbiota in nutrition and health. BMJ. (2018). 

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