The days are getting longer, and whether you’re back in the office or still working from home, where you’re not exposed to the stimuli of co-workers and commuting, keeping consistent energy levels throughout the day can be a struggle. While coffee may be most people’s go-to energy source, food is often a better option.

To help figure out the best energy-boosting foods to eat, we asked three registered dietitian nutritionists for recommendations.

In general, the experts interviewed for this story recommend eating something every three to five hours. “This typically means three meals and one to two snacks,” said Amy Gorin, a plant-based registered dietitian. “If you wait too long to eat, your blood sugar levels could crash, and you’ll get that unpleasant hangry feeling.” For every meal and snack, Gorin says to aim for a combination of protein, healthy fats and fibre to help keep you full and energised for longer.

Energy-Boosting Foods

Black Beans

This affordable cupboard staple packs a punch in the nutrition department. “Not only are black beans delicious and versatile, they are an excellent source of plant-based protein, gut-healthy fibre and energy-boosting carbs,” Meredith Price, plant-based registered dietitian nutritionist at Priceless Nutrition & Wellness, told HuffPost. “They’re also a great source of iron, which is important for energy as iron plays a role in haemoglobin, which helps carry oxygen in the bloodstream around the body.” She notes that a dish with black beans makes a great post-workout meal, as it will replenish your protein and carb stores and give you energy to take on the rest of the day.

Bananas

“These portable fruits are a great way to quickly get a boost of energy from their naturally occurring sugar, fructose, which is a carbohydrate,” Price said. As an added plus, bananas are easily digested. “The fructose gets turned into glucose and enters our bloodstream where our cells, especially our brain cells, can use it for quick energy,” she added.

Eggs

There are so many easy, delicious ways to prepare eggs ― just throw in a complex carb and some veggies and you’re good to go. “Eggs are a cheap powerhouse of complete protein and nutrients that help with energy metabolism and slow sugar absorption in the bloodstream when paired with carbohydrate foods,” said Jonathan Valdez, owner of Genki Nutrition and New York City media spokesperson for the New York State Academy of Nutrition and Dietetics.

Water

While you may not think of water as a food, two of the registered dietitian nutritionists interviewed for this story praised water, so it’s worth mentioning. “One of the biggest signs of dehydration is fatigue, because your body is running low on fluids, which means oxygen isn’t getting to where it needs to go quick enough,” Price said. “Keeping yourself well-hydrated with water can quickly turn that fatigue into a boost of energy, especially if you continuously drink all day, regardless of if you’re thirsty.” She notes that the general recommendation is to drink half of your body weight in ounces of water (75 ounces of water per day for a 150-pound person). 

“If your urine is darker than a pale yellow, you aren’t drinking enough,” Valdez said. He added that being dehydrated can often be mistaken for hunger and will also leave you fatigued.

Pistachios

For a high-protein, energy-boosting snack, pistachios are a great option. “They’re a complete plant protein and offer 6 grams of protein per quarter-cup serving,” Gorin said. “This means that they help fuel your body with essential amino acids. Plus, pistachios also provide fibre and better-for-you unsaturated fats. This trio of protein, fibre and fat helps keep you fuller for longer and provides sustained energy.” 

Energy-Draining Foods 

Caffeine/Energy Drinks

While this may seem counterintuitive, Valdez points out that consuming these types of beverages later in the afternoon can keep you from getting a good night’s sleep and leave you tired the next day. “In addition, when large amounts are consumed at once, it can lead to a caffeine crash five hours after consumption, especially when the recommended seven to nine hours of sleep is not achieved,” he said. “It is recommended to not drink caffeine within eight hours of your planned sleep.”

Sweets

For a midday boost, step away from the candy. “I love sweets just as much as the next person, but I wouldn’t eat it for an energising snack,” Gorin said. “Sugary sweets provides a momentary burst of energy, but then results in an energy zap.”

Steak

If you’ve ever felt sleepy after eating a steak dinner, you’re not alone ― and there’s a reason why. “If you order an 8-ounce steak at a restaurant, you’ll be getting a ton of protein (around 40 grams) and a lot of fat,” Price said. “Since the body can only utilise 25 grams of protein in one sitting, after eating a steak your body has to go into overdrive digesting and metabolising this extra protein.” She added that since protein isn’t the body’s preferred energy source, it will either be excreted or stored as fat. “For these reasons, your energy will be drained and you’ll likely feel sluggish and overly full.”

Fruit Smoothies

A fruit-filled smoothie may seem like a convenient, healthy meal replacement or snack, but without the right balance of ingredients your blood sugar levels will spike and you’ll feel hungry accompanied by an energy slump shortly afterward. “Smoothies remove the natural fibre content of whole fruits,” Valdez said. “The fibre and chewing required for whole fruits slow down the absorption of sugars into the bloodstream. Without the fibre and time lag of chewing, quick consumption can lead to high sugars in the blood followed by a sugar crash from the release and then work of insulin.”

Low-Calorie Frozen Meals

“If you’re relying on one of these freezer meals for lunch or dinner, you may notice that some of them are around 300 calories (or less!) while being extremely high in sodium,” Price said. In addition to not providing enough calories for a full meal (and therefore not sufficiently fuelling your body), she points out that the high amounts of sodium will lead to water retention, bloating and an overall feeling of fatigue. “If you’re in a rush and don’t have time to cook, aim for a frozen meal that’s at least 450-500 calories and has less than 20 percent of the daily value of sodium.”