It usually happens around 3pm: That moment when your focus starts lagging, your brain gets a little hazy, and it feels like an eternity until dinner. You may be inclined to grab a snack to boost your energy—something sweet or carb-heavy, perhaps. Yet, when your refreshment choice backfires, you can end up feeling even worse. Welcome to the dreaded afternoon slump.

If you want to tame your p.m. fatigue, says Maya Feller, RDN, you first need to look at where it’s is coming from. “The afternoon slump can be a result of a number of diet and lifestyle factors,” explains the nutritionist. To prevent a crash before it happens, she suggests getting plenty of sleep; staying hydrated; eating protein and carbs for breakfast while avoiding sugary, caffeinated beverages; and choosing a lunch made from non-starchy veggies, plant-based fats, and lean proteins. “These meals offer steady blood sugar control, so there are fewer highs and lows,” says Feller.

And what if you’ve done all that and you still need help getting over the final hump of your day? According to Feller, it’s fine to have a late-afternoon snack—just make sure you’re mindful about it. “I encourage afternoon snacks that provide sustained energy, rather than heavily processed, sugary ones that give a boost followed by a crash,” she says. Her number-one tip: “Combine nutrient-rich fruits or veggies that give quick energy and hydration with a lean protein or fat for staying power.”

Here, Feller shares her favorite foods for combatting an afternoon slump, plus the ones you should banish from your snack drawer. Yes, it’s hard to say goodbye to your cookie stash. But it’s gotta be better than trying to steal 15-minute naps in your office conference room, right?

Here’s what to eat (and what to avoid) when you feel end-of-day fatigue coming on.

The worst foods to eat during an afternoon slump

Granola bars: “Some are made with oats, sugar, honey, and fruit,” explains Feller. “Yes, the ingredients are healthy—however the amount used and combination can lead to a glucose spike, followed by a rapid dip.” If you’re on the go and a bar is your only option, look for ones that have 5g of sugar or less per serving and ingredients that you recognize.

“All-fruit” smoothie drinks: These also contain high amounts of sugar, once again setting you up for a crash. “The trick is to provide a balanced boost rather than a sugar-filled one,” says Feller.

Fruit-based yogurts with added sugars: Some yogurts have more than 25g of sugar—which equals 6.25 teaspoons of the sweet stuff. (Yikes.) If you really don’t want to give up your yogurt habit, Feller says to make a parfait from plain, unsweetened yogurt, 1/4 cup fresh fruit, and 1/4 cup nuts.

Carb-heavy vending machine staples: Pastries, pretzels, chips—all of these things may sound super tempting around 3pm, but they’ll just make your fatigue worse. “Carbs are the body’s preferred source of energy and can provide the brain with the pick-me-up that it’s looking for,” says Feller. “But these are simple carbs that cause your blood sugar to spike and crash, leaving you feeling tired.”

What to eat for a post-lunch energy boost

Veggies and dip: Feller loves combining a sandwich-sized bag of non-starchy veggies—think cherry tomatoes, cucumbers, carrots, or baby bell peppers—with one serving of hummus, plain yogurt, or guacamole. If you want to spice things up a little bit, you can season the veg with lime and chili pepper, and you’ve also got the option to sub the dip for an ounce of cheese.

Fruit and cheese plate: Fruit’s a great choice in the afternoon, says Feller, as long as you balance it out with protein and fat, like a serving of nuts and one ounce of cheese. (Or vegan cheese, if that’s your thing.)

Homemade nut mix: This one’s totally customizable—just blend your choice of mixed nuts and seeds with golden raisins. The key is to make sure you’re only eating 1/4 cup of the mix per serving, says Feller.

Popcorn mix: For a satisfyingly crunchy snack, mix air-popped popcorn with a serving of nuts and dry-roasted chickpeas or edamame. And be sure to make some extra—this one’s also a great choice for after-work Netflix binges.

Pair your snack with this energy-boosting turmeric tonic recipe—and follow these tips for keeping your cortisol levels in balance (also key to avoiding the mid-day slump.)