5:2 Fasting for Athletes: What to Eat on 500-Calorie Days

By Kaitlin Ahern | June 18, 2019


You’ve probably heard about intermittent fasting and its many purported benefits on weight management and athletic training. You may even be interested in trying the popular 5:2 fasting method, which calls for five days of normal eating mixed in with two “fast days,” where you consume only about 500 to 600 calories.

But, you may be wondering: As an athlete, how the heck do I make sure I’m getting enough nutrients on my fast days to support my training? We asked Serena Hunt, a Brooklyn-based registered dietitian-nutritionist, for the low-down on low-calorie days:

1. Coordinate your diet and training schedule. A fast day should never fall on the same day as a hard workout, Hunt says, because you’ll need more than 600 calories to support your recovery from intense training.

2. Stay hydrated. "Remember that hydrating with unsweetened tea, coffee, or water will not break your fast,” Hunt says. “Caffeine is especially helpful because it has an appetite-suppressing effect.”

MORE: 7 Naturally Hydrating Foods to Pair With a Sweaty Summer Workout

3. Eat foods loaded with healthy fat, protein, and fiber. "Healthy fat helps to reduce inflammation in our body while delaying gastric transit, meaning that food sits in our stomach longer and gives us a 'full' feeling," Hunt says. "Protein controls blood sugar and helps prevent us from feeling lightheaded on a low-calorie day. And fiber has the dual effect of increasing satiety by delaying gastric transit and controlling blood sugar.”

Fasting Day Meal Planning

Hunt created the following 500- to 600-calorie vegan, omnivore, and pescetarian meal plans to be packed with the nutrients your training body needs to get through a fasting day. Bonus: They’re all gluten-free, too!

610 calories, 36 g protein

Green Smoothie
Yields 2 servings
Per serving: 250 calories, 5 g of fat, 31 g of carbs (5 g fiber), 23 g of protein

1 medium banana
1/2 cup vegan protein powder, vanilla
2 tablespoon chia seeds
2 1/2 cups spinach or kale
2 cups unsweetened almond/coconut milk

Directions: Blend and enjoy!

Why Hunt Likes It: The fiber in the greens, banana, and chia seeds will help control blood sugar, while the protein and fat will help keep you fuller longer. If you are doing any kind of physical activity on your fasting day, it's a good idea to drink this afterward to replenish.

Greek Chickpea Salad
Serves 2
Per serving: 360 calories, 20 g of fat, 34 g of carbohydrates (9 g of fiber), 13 g of protein

1 tablespoon fresh dill, chopped
1/8 cup extra virgin olive oil
Juice of 1 lemon
1/8 tsp sea salt
1/8 tsp black pepper
1 cup canned chickpeas, drained
1/2 cucumber, diced
1 tomato, diced
1 bell pepper, diced
1 cup kale, chopped
1/4 cup feta cheese

Directions: Combine ingredients in a bowl. Mix and enjoy!

Why Hunt Likes It: This salad is loaded with protein and fiber to keep you full. Veggies are a great way to pack in volume for minimal calories while also boosting the nutrient density of your overall intake.

515 calories, 25 g protein

Fat Bomb Coffee
Serves 1
Per serving: 190 calories, 20 g of fat, 0 g of carb, 1 g of protein

1 cup high-quality brewed coffee
1 tablespoon grass-fed ghee or butter (such as Kerrygold brand)
2 tablespoons canned coconut milk 

Directions: Blend ingredients in a blender. Enjoy!

Why Hunt Likes It: If fasting intimidates you, start your day with a cup of fat-laden coffee! The combo of fat and caffeine is a powerful way to reduce appetite. Just be aware that the quality of the fat is important. Be sure to use grass-fed ghee or butter to reduce inflammation and keep your heart healthy.

Stuffed Peppers
Serves 4
Per serving: 325 calories, 18 g of fat, 20 g of carb (6 g fiber), 24 g of protein

6 red/yellow peppers
1/2 cup parmesan cheese
1 cup cauliflower rice
1 cup cooked rice
2 eggs
1 tablespoon garlic powder
1 tablespoon onion powder
1/2 tablespoon dried basil
1 lb ground beef (grass-fed)
Salt & pepper to taste

Directions: Slice the tops off the peppers and remove the seeds. In a large bowl, combine cheese, cauliflower, rice, parsley, and spices. Add eggs and mix. Set aside. Heat a large pan over medium heat and sauté the ground meat. Season with salt and pepper. Cook for about 8 minutes or until meat is browned and cooked through. Combine with the cheese mixture. Preheat oven to 350*F. In a baking tray, add enough water to just cover the bottom. Sit the peppers upright, and stuff them with the beef mixture. Cover with foil and bake for 30 minutes. Remove the foil and broil for 5 minutes before serving.

Why Hunt Likes It: These peppers are loaded with fiber, protein and healthy fat to keep you feeling full.

555 calories, 32 g of protein

Avocado Wrapped with Lox
Serves 2
Per serving: 220 calories, 17 g fat, 9 g carbs (7 g fiber), 11 g protein

1 avocado, skin removed and sliced into 8 long pieces
3 1/2 ounces of salmon lox

Directions: Wrap each slice of avocado with salmon and enjoy.

Why Hunt Likes It: This is a great way to start a fasting day because the salmon’s protein helps to balance blood sugar and boost “muscle protein synthesis” or the creation of new lean body mass. Salmon and avocado lend the athlete healthy omega-3 fatty acids and monounsaturated fatty acids, respectively, which reduce inflammation and protect our heart from disease.

Tuna Bowls
Serves 4
Per serving: 335 calories, 12 g fat, 36 g carb (6 g fiber), 21 g protein 

10 ounces cooked tuna or 2 cans of tuna in water, drained
1 sweet potato
1 red pepper
3 leeks, chopped
1 cup red onion, chopped
2 garlic cloves, minced
1 tablespoon extra-virgin olive oil
1 tsp red pepper flakes
1 1/2 cups cooked quinoa
Arugula or other leafy green
Dill, chopped
1/4 cup crumbled feta cheese
1 lemon
Salt and black pepper

Directions: Mix sweet potato, red bell pepper, red onion, leeks, and garlic cloves in a large mixing bowl. Toss well with red pepper flakes and olive oil. Place veggies on a foil-lined baking sheet and roast veggies in an oven preheated to 400*F for about 30 minutes. Remove from oven and let cool. Separate into four bowls for serving, building a bowl with quinoa, dill, feta, leafy greens, roasted veggies. Squeeze lemon, salt, and pepper on top and eat with fish.