What Food is Only 30 Calories? A Guide to Light, Healthy Snacking

October 23, 2025 •

4 min read

One hundred grams of watermelon contains only about 30 calories, making it a perfectly sweet and hydrating snack option. This fact highlights a key principle of healthy eating: many delicious and satisfying foods are naturally low in energy. So, what food is only 30 calories, and how can you integrate these options into your daily diet?

Quick Summary

This guide covers a variety of nutritious fruits, vegetables, and other simple snack ideas that contain approximately 30 calories per serving. Learn how to incorporate these flavorful and low-calorie foods to support your health goals effectively.

Key Points

Watermelon is a key 30-calorie food: A 100-gram serving offers hydration and natural sweetness for approximately 30 calories.
Vegetables offer numerous sub-30 calorie options: Cucumbers, celery, cauliflower, and spinach all provide high fiber and low-calorie volume for satisfying snacks.
Berries are a flavorful, low-calorie choice: Strawberries and blueberries contain just over 30 calories per 100 grams while delivering antioxidants and vitamins.
Crunchy snacks can be low-calorie: Air-popped popcorn is a satisfying whole-grain snack with about 30 calories per cup.
Strategic snacking is essential: Pre-portioning low-calorie snacks and pairing them creatively can help manage hunger and support weight goals.
Enhance flavor without adding calories: Using herbs, spices, and calorie-free seasonings can boost the taste of low-calorie vegetables and fruits.

Fresh and Juicy: Fruits with Around 30 Calories

Fruits are an excellent source of vitamins, fiber, and natural sweetness without excessive calories. Many water-rich fruits fall into the 30-calories-per-serving category.

Watermelon

As mentioned, watermelon is a superstar for low-calorie snacking. A 100-gram serving (about 2/3 cup, diced) provides a refreshing treat with a powerful hydrating effect. The amino acid arginine found in watermelon may also help burn fat quickly, supporting weight loss efforts.

Strawberries and Blueberries

Small but mighty, berries are packed with antioxidants and fiber. Approximately 100 grams of strawberries contain around 32 calories, while the same amount of blueberries is also about 32 calories. Both are versatile and can be added to yogurt, oatmeal, or enjoyed on their own.

Grapefruit

Certain varieties of grapefruit are very close to the 30-calorie mark. A 100-gram serving of pink and red grapefruit has about 30 calories. This citrus fruit is also a fantastic source of vitamin C and pectin, a soluble fiber that promotes fullness.

Earthy and Crunchy: Vegetables for a Low-Calorie Boost

Vegetables are incredibly nutrient-dense and offer a wide range of low-calorie choices for snacking. Eating them raw maximizes their water and fiber content, which helps with satiety.

Cucumbers: Containing only about 16 calories per 100 grams, cucumbers are one of the lowest-calorie vegetables available. Their high water content makes them incredibly refreshing.
Celery: At around 16 calories per 100 grams, celery is another crisp, water-filled option. Its fibrous structure requires more chewing, which can help signal fullness to the brain.
Cauliflower: With about 25 calories per 100 grams, cauliflower is a versatile and filling vegetable. It can be eaten raw with a low-calorie dip, or roasted for a more savory flavor.
Spinach: A powerhouse of vitamins and minerals, spinach has about 23 calories per 100 grams. It's great in salads or lightly wilted for a warm snack.
Radishes: Offering a peppery kick for very few calories (around 19 per 100 grams), radishes are a great way to add crunch and flavor to your snacks.

Simple Snacks and Flavor Boosters

Sometimes, a 30-calorie snack isn't a single food item but a combination or a small portion of something else.

Air-Popped Popcorn: A single cup of plain, air-popped popcorn contains roughly 30 calories. It offers satisfying crunch and fiber, making it an excellent alternative to higher-calorie chips.
Clear Vegetable Broth: For a savory, warming snack, a cup of clear vegetable broth can provide rich flavor for only about 10 calories.
Pickles: Most dill pickles are extremely low in calories, with a medium-sized pickle containing around 7 calories. Several spears can make a satisfying, crunchy snack.
Egg White: One large egg white contains about 17 calories and is a great source of pure protein with no fat or cholesterol.

Low-Calorie Food Comparison Table


Food (100g serving)	Calories (approx.)	Primary Benefit	Serving Idea
Watermelon	30 kcal	Hydration, Natural Sweetness	Diced, frozen into cubes, or blended into a smoothie.
Cucumbers	16 kcal	High Water Content, Refreshing	Sliced with a sprinkle of pepper or dipped in low-fat cottage cheese.
Cauliflower	25 kcal	Fiber, Versatility	Raw florets with a low-calorie dip or lightly roasted.
Spinach	23 kcal	Vitamins, Minerals	Raw in salads, wilted into a broth, or as a bed for other foods.
Air-popped Popcorn	30 kcal (per 1 cup)	Fiber, Texture, Whole Grain	Plain, with a dash of nutritional yeast for flavor.
Strawberries	32 kcal	Antioxidants, Vitamin C	Eaten fresh, frozen, or added to unsweetened yogurt.

How to Strategically Incorporate 30-Calorie Foods

Maximizing the benefits of these low-calorie options requires a strategic approach. It's not just about eating less but about eating smarter. Instead of mindlessly snacking on high-calorie foods, pre-portioning these healthier alternatives can help manage overall intake.

Meal Prep: Chop up vegetables like cucumbers, celery, and radishes at the beginning of the week. Store them in the fridge for easy access when a craving hits.
Flavor without Calories: Use herbs, spices, and calorie-free seasonings to enhance the taste of these foods. A spritz of lemon juice on a salad or a sprinkle of chili flakes on cucumber slices can make a significant difference.
Combine and Conquer: Pair a low-calorie vegetable with a small amount of a slightly higher-calorie, nutrient-dense food. For instance, dip carrot sticks (which have a few more calories) in a tablespoon of low-fat Greek yogurt.

For more detailed nutritional information on many fruits, you can consult resources like the FDA's Raw Fruits Poster.

Conclusion

Finding a food that is only 30 calories is simpler than you might think. By focusing on water-rich fruits and high-fiber vegetables, you can create a satisfying and healthy snacking routine. Options like watermelon, berries, cucumbers, and air-popped popcorn prove that you can indulge your cravings and feel full without consuming a significant number of calories. Incorporating these nutrient-packed, low-calorie foods into your diet is a smart and sustainable way to support your overall health and wellness goals.

Frequently Asked Questions

While precise calorie counts vary slightly, watermelon is known for being extremely close to 30 calories per 100-gram serving. The pink and red varieties of grapefruit also fall around this mark.

The term 'negative calorie' refers to foods that supposedly burn more calories to digest than they contain. However, this is largely a myth. Foods like celery and cucumbers are very low in calories, but they still provide some energy.

Yes, you can eat a generous quantity of these foods because of their high water and fiber content. This helps promote a feeling of fullness, which can reduce overall calorie intake and support weight management.

Absolutely. Foods like watermelon, berries, spinach, and cauliflower are packed with essential vitamins, minerals, and antioxidants, making them both low in calories and high in nutritional value.

In nutrition, the terms 'calorie' (often capitalized as Calorie) and 'kilocalorie' (kcal) are used interchangeably to refer to the same unit of energy. The foods mentioned in this article are measured in kilocalories, but it is common practice to simply call them calories.

You can make low-calorie vegetables more flavorful by adding herbs, spices, a dash of lemon juice, or pairing them with a small amount of a low-fat dip like Greek yogurt or hummus. Roasting or grilling them can also enhance their natural flavors.

Yes, a single cup of air-popped popcorn without any oil or butter is approximately 30 calories. It is a great source of whole grains and fiber, but adding toppings will significantly increase its calorie count.