What Can I Eat for 18 Calories? A Guide to Nutrient-Dense, Low-Calorie Foods

October 24, 2025 •

4 min read

According to the USDA, a standard cup of sliced cucumber contains approximately 18 calories, making it a perfect example of what can I eat for 18 calories. While 18 calories is a small amount, focusing on nutrient-dense foods that offer high volume for minimal energy can be incredibly satisfying for managing weight and curbing hunger. This guide explores various healthy options that meet this tiny caloric threshold.

Quick Summary

This article explores a variety of whole food options, primarily vegetables, and fruits, that contain roughly 18 calories per serving. It details their nutritional benefits, practical usage in meals and snacks, and provides recipes to make them more flavorful and satisfying. Examples include radishes, cucumber, and certain mushrooms, demonstrating how to make the most of minimal calories.

Key Points

Cucumber: A 1-cup serving of sliced cucumber offers approximately 18 calories, making it a perfect low-energy snack.
Radishes: One cup of sliced radishes contains about 18 calories and provides a peppery, crunchy, and refreshing bite.
Bell Pepper: A small portion of green bell pepper, like a generous slice or a handful of diced pieces, falls under the 18-calorie limit.
White Mushrooms: A full cup of sliced, raw white mushrooms is only about 15 calories, offering a significant portion for minimal calories.
Celery: A single stalk of celery contains fewer than 6 calories, so two or three stalks would fit the 18-calorie guideline.
Apricot: One raw, medium apricot contains approximately 16 calories, providing a sweet, low-calorie fruit option.
Hydration is Key: Many very low-calorie foods, like cucumber and celery, have high water content, contributing to a feeling of fullness.
Enhanced Flavor: Using seasonings like lemon juice, black pepper, or sea salt can add flavor to these foods without adding significant calories.

Making Every Calorie Count: The Strategy Behind Very-Low-Calorie Foods

When you're focused on a specific calorie target, especially a very low one like 18, the goal is not to fill up but to select foods that provide the most nutritional value and volume. These items often have a high water content and fiber, which helps create a feeling of fullness. Focusing on a handful of such foods can be an effective way to manage hunger pangs between meals without compromising your diet. The key is to see these as small, nutritional boosts rather than full snacks.

The Super-Sleuth's Guide to Tiny Bites

While few items are exactly 18 calories, many common fruits and vegetables fit neatly into this category or can be portioned to do so. These foods are often referred to as 'negative calorie' foods, though this is a myth, as all foods contain some calories. The term simply highlights their low energy density. A single raw, medium-sized apricot, for example, contains approximately 16 calories, placing it perfectly in this range. A handful of radishes, around a cup of sliced pieces, also hits the 18-calorie mark. These tiny nutritional powerhouses are often overlooked but offer great crunch and flavor.

Delicious Ways to Enjoy 18-Calorie Snacks

Radish slices with lemon juice and black pepper: A cup of thinly sliced radishes provides 18 calories and a zesty, peppery kick. A squeeze of fresh lemon juice adds flavor with virtually no extra calories.
Cucumber rounds with a mint garnish: A cup of sliced cucumber is approximately 18 calories and is incredibly hydrating. Garnish with a few fresh mint leaves for a refreshing taste.
Half a cup of sliced white mushrooms: Raw mushrooms are extremely low in calories, with half a cup providing just under 8 calories. You can double this portion and still be within the 18-calorie target, or sauté them in a non-stick pan with a little water and seasoning for a flavorful warm bite.
A single bell pepper slice with a pinch of sea salt: An entire green bell pepper contains only about 25 calories, so a thick slice (or a small handful of diced pieces) easily falls under 18. A small sprinkle of sea salt can enhance its natural flavor.
Four large strawberries: One cup of strawberries contains 53 calories, meaning around four medium to large berries will be under 18 calories. They offer a sweet, antioxidant-rich treat.

Comparison of Low-Calorie Snack Options


Food Item	Approximate Serving for 18 Calories	Key Nutrient Highlights	Best Way to Eat
Cucumber	1 cup sliced	Vitamin K, high water content	Raw slices, hydrated snack
Radishes	1 cup sliced	Vitamin C, folate, potassium	Raw slices, peppery crunch
White Mushrooms	1 cup sliced	B vitamins, vitamin D, selenium	Raw in a salad or sautéed lightly
Celery	~3 medium stalks	Dietary fiber, vitamin K	Plain or with a light dusting of spices
Bell Pepper (Green)	< 1 small bell pepper	Vitamin C, B6	Raw strips or diced for a salad
Apricot (Raw)	1 medium fruit	Vitamins A, C, E	Enjoyed fresh for a sweet bite

Advanced Tips for a Calorie-Conscious Diet

For those looking beyond just the immediate 18-calorie snack, it's important to consider hydration and meal composition. Drinking a glass of water before a meal or snack can contribute to a feeling of fullness. Additionally, integrating these very low-calorie items into larger, healthy meals can help boost volume without adding significant calories. Use sliced cucumber or bell peppers to top a lean protein salad, or add radishes to a stir-fry. While these simple items are not meant to sustain you over long periods, they are excellent tools for controlling portion sizes and practicing mindful eating. Small, frequent, nutritious portions can help maintain consistent energy levels and regulate appetite. The key is consistency and combining these low-calorie items with a balanced diet.

Conclusion: The Power of Small, Nutrient-Dense Choices

Finding what can I eat for 18 calories is a thought exercise that reveals the wide range of nutritious and satisfying options available in small portions. From the crisp bite of a radish to the hydrating crunch of cucumber, these foods offer more than just low calories—they deliver essential vitamins, minerals, and fiber. Embracing these small, nutrient-dense choices can be a practical and effective strategy for managing weight and maintaining a healthy diet. By focusing on whole, unprocessed foods, you can enhance flavor and feel satisfied, even with just a tiny energy investment. The takeaway is that a diet built on nutrient-rich foundations can make a small number of calories feel surprisingly substantial. For further reading, Harvard Health offers excellent general advice on low-calorie snacks and healthy eating, providing a broader context for these tiny dietary decisions.

Frequently Asked Questions

For hydration, a cup of sliced cucumber is an excellent choice. It consists of over 95% water and is about 18 calories per cup, making it a refreshing and low-calorie snack.

An 18-calorie snack is unlikely to make you feel full on its own. However, high-volume, low-calorie foods with high water and fiber content, like cucumber or celery, can contribute to a sense of fullness and help manage appetite when combined with a balanced diet.

Yes, one medium-sized raw apricot is approximately 16 calories, so it fits the 18-calorie range perfectly. A small handful of strawberries (around four) also comes in at this calorie level.

You can add flavor with low-calorie seasonings like black pepper, a squeeze of lemon or lime juice, a sprinkle of fresh herbs (like mint or cilantro), or a dash of hot sauce. These options add flavor without significantly increasing the calorie count.

The main benefit is managing overall calorie intake while consuming nutrient-dense foods. These items provide vitamins, minerals, and fiber, helping to curb hunger and provide nutritional value with minimal energy, which is important for weight management.

The concept of 'negative calorie' foods is a myth. While foods like celery and cucumber are very low in calories, your body does burn some energy to digest them. However, it's a minimal amount, so the net calorie gain is still very low.

Sautéed white mushrooms are a great cooked option. Since a cup of raw mushrooms is about 15 calories, you can lightly sauté them with a little water and a pinch of salt to create a flavorful warm snack while staying under 18 calories.