Energy slumps during the day can tell you many things — they might mean that your brain needs a mental break or that you’re reeling from a rough night of sleep. Unfortunately, these slumps could also be influenced by the foods you’re eating (or not eating).

Skipping meals or snacks because you’re busy — or because you don’t have the time to fix something to eat — can be a leading reason why you feel tired during the day, according to Katie Janeczek, RDN. Your body needs glucose from carbohydrates to produce energy, plus protein and fiber to satisfy your hunger. Feeling too hungry can cause your energy levels to drop.

For this reason, dietitians advise eating when your body is telling you it’s hungry, explains Maya Feller, RD. Try to avoid going more than five hours without eating. And when it’s time to eat, be conscious of energy-zapping foods that could be making your day harder than it needs to be.

Why do some foods make you tired?

Foods that shoot up your blood sugar levels quickly also allow them to swoop down drastically in a short amount of time, Feller and Janeczek explain. You’re likely to get a really quick burst of energy, but crash around 30 to 60 minutes afterwards and feel tired again.

6 foods that zap your energy

1. Sugary beverages

Sodas, sweet teas, lemonade, sugar-sweetened waters, and energy drinks are all packed with sugar that can deplete your energy levels. A can of soda contains around 10 teaspoons of sugar, while a can of Red Bull contains 9 to 12 teaspoons of sugar.

2. Fruit juices

While the label often says there isn’t any added sugar, the ultra-processed nature of juices means that there is little to no fiber left, leaving just the free-floating sugars. There are five to nine teaspoons of sugar in every eight-ounce cup of juice.

3. Foods made with white flour

Biscuits, crackers, white bread, and pizza are all examples of foods made with white flour, a refined carbohydrate. Albeit delicious, they do not offer the steady energy that you may be after.

4. Chips and crisps

Chips and crisps are ultra-processed, refined carbohydrates. Not only that, but they also may contain saturated fat, hydrogenated oils, or trans fat, which can affect your blood cholesterol.

5. Chocolate and candy

These are sugary sweets that fall into the ultra-processed food category. They aren’t the best snacks to reach for if you want to prevent that spike in your blood sugar level. However, don’t let that keep you from having a sweet treat every now and then!

6. Baked treats

Cakes, cookies, donuts, and pastries are made from white flour and generally sweetened with a good amount of sugar. Keep in mind that this doesn’t mean you must strictly avoid all these foods. Instead, balance them with nutritious meals so they won't drastically affect your energy levels.

(Real Simple magazine provides smart, realistic solutions to everyday challenges. Online at www.realsimple.com.)

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