Why Do I Feel Tired After Eating? An Investigation of the Causes

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From personal experience, I can certainly say the afternoon slump is real. One minute I'm happily typing away at my desk, and the next I catch myself staring off into a void, yearning for a pillow, a blanket, and the sweet serenity of a nap. Sometimes the fatigue sets in so quickly that my body feels like it's hit an actual brick wall. With my feet dragging, my eyelids drooping, and a yawn on my lips, I head to the coffeepot for a quick cup of caffeinated revival.

This isn't a problem if it happens occasionally. It is a problem, though, if it happens all the time—like it did for me. You see, for a few months, fatigue set in like clockwork around 1:30, which happens to be the middle of the workday. It also happens to be right after I eat lunch. Upon doing some research (i.e. asking people sitting in my general vicinity), I found that feeling tired after eating is a quite common occurrence. Almost everyone chimed in with an "I hate when that happens" or a "Yeah, why is that?"

I didn't have the answers, but nutritionist and Food Coach NYC & LA founder Dana James and Lisa Moskovitz, RD, CDN, and CEO of NY Nutrition Group did.

Keep scrolling to learn why you get tired after eating, and how to prevent it.

Lay Off the Carbs

If you often want to take a nap after eating, your blood sugar could be to blame: "The more carbs you eat the higher our insulin levels climb," says Moskovitz. "When insulin levels peak this could contribute to a blood sugar crash causing tiredness, fatigue, and even potential sugar cravings."

"It's not normal to feel tired after eating," James says. "It's the composition of the meal (e.g., it's too high in carbs) or you have a food sensitivity to one of the ingredients, most often wheat. If you don't want to feel tired, drop the bread, grain bowls, pasta, noodles, and sushi rolls and instead focus on loads of vegetables (which are vitalizing) and a palm-size amount of protein. Add a hint of fat to keep you satiated for longer."

"Quick-digesting carbs, or sugar-laden foods, are typically the biggest culprits behind sudden energy crashes," says Moskovitz. "A higher fat meal might also make you sleepy as it slows down digestion leading to a much slower energy supply."

Check for Allergies

So it could be as easy as cutting out carbs (don't shoot the messenger), but if you still experience physical and mental fatigue, ask your doctor about testing for food sensitivities, which both experts say may cause inflammation inside the body. As James said, wheat is the most common one, though it could be any type of food.

Eat More Regularly

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Another way to tackle low blood sugar is by eating more regularly, which worked for me. "Eating at regular intervals throughout the day, or every 3-4 hours can also make a difference in how you feel both before, and after, meal times," notes Moskovitz. Adjusting my diet and eating more regularly nixed the fatigue issue from my life.

Drink Coffee in Moderation

"Coffee can offer a quick energy boost but don't forget: what goes up must come down," notes Moskovitz. "You might notice an immediate improvement in motivation and concentration but after that caffeine wears off, you might be back to where you started, or even more tired than before. That said, coffee can definitely be safe in moderation, or under 400mg per day, depending on the person, but it's best to figure out the real cause behind that fatigue before ignoring it with caffeine." 

Sometimes, it's as simple as not getting a goodnight's sleep: "The effects of insufficient sleep might not be noticeable until you have a full tummy," notes Moskovitz.

Get Your Nutrients

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"Micronutrients such as B-vitamins, vitamin D, and iron, can also help fend off fatigue. B-vitamins help convert the food you eat into energy, vitamin D deficiency can affect energy levels, and iron is key to help circulate oxygen in your blood," says Moskovitz. If the fatigue sticks around despite healthy changes, you might need to enlist the help of a supplement, assuming you have your physician's approval. Just remember, as James puts it, "food before supplements," always.

Try a Chromium Supplement

Chromium can be taken each day "to stabilize blood sugar levels," says James. She recommends taking 300 mg with both lunch and dinner to control minor swings in blood sugar and, thus, energy. Everyone's a little different, though, so what works for one person might not work for another. Your personal doctor or nutritionist will be able to help you decide what's best before making any big changes to your diet.

Incorporate Moderate Exercise

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"Moderate exercise, sufficient sleep, and hydration are also important for to fight against fatigue," says Moskovitz. If your schedule allows, build bursts of exercise in throughout the day to perk you up; i.e. instead of a post-lunch nap, try a post-lunch walk or twenty-minute yoga session.

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