Afternoon Fatigue: 6 Ways Your Diet Could Be Making You Tired

Afternoon Fatigue: 6 Ways Your Diet Could Be Making You TiredDo you experience afternoon fatigue where your energy level plummets and you need to grab a cup of coffee just to stay awake? If you’re getting enough sleep at night and are otherwise healthy – it may be your diet. Making a few changes to how and what you eat could be the key to feeling more energetic and staying productive throughout the day. That’s certainly better than barely keeping your eyes open! Here are some of the most common dietary mistakes that can cause your energy level to plummet and afternoon fatigue.

Afternoon Fatigue: Not Spacing Your Meals and Snacks Properly

Are you going long periods without eating a meal or snack? That can send your blood sugar and energy level crashing in the afternoon. Eat a small snack every three hours throughout the day to help maintain a steady blood sugar level. Three meals a day and two snacks evenly spaced is ideal if you want to stay focused, motivated and alert.

Choose your snacks wisely. Select ones that are high in protein and fiber-rich carbs like a handful of nuts, almond butter on a whole grain cracker, string cheese, tuna fish on crackers or a container of low-sugar yogurt. The protein in these snacks will help you avoid blood sugar peaks and valleys that zap your energy. They’ll also keep hunger at bay.

 Afternoon Fatigue: Overzealous Calorie Restriction

Calorie restrictive diets can take their toll on your energy level – and on your metabolism. Never drop your calorie intake more than 500 calories a day when you’re trying to lose weight. Make sure you’re selecting nutrient-rich foods and limiting sugary drinks, juices, processed carbohydrates and added sugar. At the same time, avoid “saving up” all of your calories for a big meal. Ever notice how easy it is to fall asleep after a large lunch or dinner? That’s because blood is diverted to your digestive tract for digestion and away from your brain. Spread your calories over the day.

Afternoon Fatigue: Too Many or Not Enough Carbs

You need a certain amount of carbs in your diet. Your brain requires glucose, although in a pinch it can use ketone bodies. People who follow an extreme low carbohydrate diet frequently complain of fatigue. At the other extreme, fueling up on too many processed carbs and sugar cause your energy level to rise and then crash as your blood sugar goes up quickly and falls just as rapidly. Some people reach for a candy bar or soft drink hoping to get a quick surge in energy. Instead they end up feeling even more tired as their blood sugar level crashes. Don’t be afraid of carbs but choose ones that are unprocessed and high in fiber.

 Afternoon Fatigue: Too Much Caffeine

Caffeine may sound like a “quick fix” for fatigue, but your body adapts to regular caffeine consumption and it starts to lose some of its pick-me-up power. As a result, you have to drink more and more to get the energizing effects. Why does this happen?

Caffeine stimulates the release of adrenal hormones like cortisol and adrenalin that your body releases during times of stress. These hormones give you a quick energy surge – but longer term it overworks your adrenal glands, leading to adrenal exhaustion and fatigue. When you keep yourself in a hyper-alert state all the time by fueling yourself with caffeine, you’re exhausted when you finally come down.

Taper back your caffeine SLOWLY. If you do it too quickly and you’ll get caffeine withdrawal symptoms like headache and, yes, fatigue. If your afternoon slump is the result of overusing caffeine, it may take several weeks for you to feel better.

Afternoon Fatigue: Not Drinking Enough Fluid

It isn’t just what you eat that can make you feel more or less energized, what you drink counts too. Fatigue can be a sign of mild dehydration. One study showed mild dehydration in women negatively impacted mood and the ability to concentrate. It was also linked with headache and fatigue.

When you’re at work or out and about during the day, it’s easy to forget to drink fluid. Take a look at your urine. It should be pale yellow in color. If it’s darker than that, you’re probably not drinking enough fluid. Carry a big bottle of water in a stainless steel thermos and sip it throughout the day. Add fruit slices or slices of cucumber for more flavor appeal. If it tastes good you’ll drink more of it.

Many people are in a state of mild dehydration and don’t realize that’s why they feel tired – don’t be one of them.

Afternoon Fatigue: Could You Be Iron Deficient?

If you’re pre-menopausal, especially if you eat a vegetarian diet, iron deficiency could be causing your fatigue. Don’t blindly take iron. You shouldn’t supplement with iron unless you need it. Instead, ask your doctor to check your blood and do an iron panel to see where you stand. Iron deficiency anemia can cause persistent fatigue, reduced exercise tolerance and lightheadedness but it’s easily correctable with iron supplements.

The Bottom Line?

If your head is nodding in the afternoon and you can’t seem to break out of that afternoon fatigue slump, take a closer look at how much you’re eating and drinking and the composition of your diet. Taper back your caffeine slowly and drink more water instead. Get up and move around more during the day. Sitting too long can cause you to feel fatigued and increase the risk for health problems as well. Keep in mind that health problems like diabetes and thyroid disease can cause fatigue too. See your doctor if you don’t feel more energetic after changing your diet.



Psychosom Med. 2005; 67(5): 734–739.

Pharmacol Biochem Behav. 2006 Mar;83(3):441-7.

Medscape.com. “Even Mild Dehydration May Cause Emotional, Physical Problems”


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