What foods have zero calories?

Quick Answer: Foods with zero calories don’t actually exist—your body burns calories digesting everything you eat. But certain foods like celery, cucumber, and leafy greens have so few calories (under 10 per 100g) that you burn nearly as much energy breaking them down, making them effectively “zero calorie” choices for weight management.

What Are Zero Calorie Foods 

The whole idea of zero calorie foods comes down to something called the thermic effect of food. Your body uses energy to chew, digest, and process everything you eat. Some foods contain so few calories that the energy you spend breaking them down almost cancels out what you’re taking in.

Most vegetables sitting under 10 calories per 100 grams (3.5 ounces) fall into this category. You’re not getting zero—you’re getting close enough that it barely registers. These foods have zero calories in practical terms for meal planning and weight control.

The bonus here is you can eat large volumes without worrying about your calorie budget. You walk away full, satisfied, and you’ve barely made a dent in your daily intake.

Non-Starchy Vegetables for Maximum Volume

Non-starchy vegetables give you the biggest return on minimal calories. We’re talking about foods that fill you up without the carb load.

Celery sits at about 6 calories per 100g (3.5 oz). You get fibre, water, and crunch. Slice it up, eat it raw with a bit of salt, or toss it into soups and stir-fries. The high water content (95%) means you’re hydrating while you eat.

Cucumber is even lower at around 8 calories per 100g. Use it in salads, as a snack with vinegar, or blend it into cold soups. Keep the skin on for extra fibre and micronutrients.

Zucchini (courgette) comes in at 17 calories per 100g. Spiralize it for a pasta replacement, grill it, or roast it with minimal oil. You can eat a full plate and stay under 50 calories total.

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Leafy Greens That Have Zero Calories Impact

Leafy greens are your absolute best option for high-volume eating. Spinach, rocket (arugula), lettuce—all sitting under 20 calories per 100g.

Spinach gives you 23 calories per 100g raw. Steam it, wilt it into eggs, or eat it fresh in salads. One cup cooked is about 7 calories. The nitrates in spinach improve blood flow and exercise performance according to multiple studies.

Lettuce varieties (iceberg, romaine, butterhead) range from 5-17 calories per 100g. Build massive salads using them as a base. You’re getting volume, fibre, and micronutrients with almost no caloric cost.

Rocket (arugula) sits at 25 calories per 100g. Toss it with lemon juice and a tiny bit of olive oil. The peppery flavour makes it more interesting than plain lettuce.

Mushrooms and Cruciferous Vegetables

Mushrooms average 22 calories per 100g across varieties. Sauté them dry in a non-stick pan—they release their own water. Button, portobello, shiitake—all work. The umami flavour makes meals more satisfying without adding calories.

Cruciferous vegetables like broccoli, cauliflower, and Brussels sprouts range from 25-43 calories per 100g. These are slightly higher but still considered very low calorie. Roast them at 200°C (400°F) for 20-25 minutes for better flavour. The glucosinolates in these vegetables support liver detoxification pathways.

Cauliflower works as a rice replacement. One cup of cauliflower rice is 25 calories versus 200+ for regular rice. You can eat four times the volume for the same caloric load.

Zero Calorie Drinks and Liquids

Water is the only true zero calorie option. Aim for 2-3 litres (68-102 oz) daily. Add lemon, lime, or cucumber slices for flavour without adding meaningful calories.

Black coffee and tea have 2 calories or less per cup. No milk, no sugar—just straight. The caffeine increases metabolic rate slightly, meaning you burn more energy at rest. Studies show green tea’s catechins may boost fat oxidation during exercise.

Herbal teas (peppermint, chamomile, rooibos) are all zero calorie. Drink them hot or cold. They keep you hydrated and give you something flavoured to sip on throughout the day.

Sparkling water is zero calories as long as it’s unflavoured or naturally flavoured without sweeteners. It gives you the carbonation satisfaction without the sugar load of soft drinks.

Frequently Asked Questions

What foods have zero calories that actually fill you up?

Celery, cucumber, lettuce, and mushrooms have the lowest calorie density while providing volume. The high water and fibre content triggers stretch receptors in your stomach, signalling fullness to your brain. Eating 200g of cucumber (16 calories) creates the same physical fullness as a small bread roll (150+ calories).

Do you burn more calories digesting celery than it contains?

This is mostly a myth. Celery contains about 6 calories per 100g, and digestion burns roughly 10-20% of those calories through the thermic effect of food. You’re left with about 5 calories net. It’s close to zero but not negative. The real benefit is eating high volumes without impacting your calorie budget.

Can I eat unlimited zero calorie foods and lose weight?

Yes, in practical terms. Your stomach has a physical limit—you’ll feel uncomfortably full before eating enough celery or lettuce to gain weight. Most people naturally stop at 500-1000g of vegetables per meal. That’s still only 50-200 calories depending on the vegetable. The fibre also slows digestion and keeps you satisfied longer.

What about zero calorie sweeteners—are they actually zero?

Stevia, erythritol, and monk fruit are effectively zero calorie. Your body doesn’t metabolise them for energy. Aspartame and sucralose have trace calories (less than 5 per serving) but are labelled zero under food regulations. They don’t trigger an insulin response in most people, making them useful for sweetening without affecting blood sugar.

Are pickled vegetables still zero calorie foods?

Plain pickled vegetables (cucumber, cabbage, radish) remain very low calorie at 10-20 calories per 100g. The pickling process doesn’t add significant calories. Watch for added sugar in commercial pickles—that can push it to 30-50 calories per serving. Make your own using vinegar, salt, and spices to keep it genuinely low calorie.

How many zero calorie foods should I eat per day?

Aim for 400-800g (14-28 oz) of low-calorie vegetables daily, split across meals. That’s roughly 2-4 cups cooked or 4-8 cups raw. This gives you micronutrients, fibre for gut health, and volume for satiety. Australian dietary guidelines recommend 5-6 vegetable serves daily—most of which can come from these very low calorie options.

Do zero calorie foods have any nutritional value?

Absolutely. These vegetables contain vitamins C, K, folate, potassium, and phytonutrients. Leafy greens are particularly nutrient-dense per calorie. You’re getting more nutrition per calorie with spinach than with most calorie-dense foods. The fiber supports gut bacteria and improves digestion. These aren’t just “filler foods”—they’re nutritional powerhouses.

What’s the best way to prepare zero calorie foods without adding calories?

Steam, grill, or roast vegetables without oil. Use spices, herbs, lemon juice, vinegar, and salt for flavour. A light spray of cooking oil (1g = 9 calories) works if you need some fat. Raw preparation with salt, pepper, and vinegar keeps it truly minimal. Avoid butter, heavy dressings, and cheese—those add 50-100+ calories per tablespoon.

Can I survive on mostly zero calorie foods?

Short term, yes—but you’d lack protein, essential fats, and adequate energy. Your body needs amino acids for muscle maintenance and omega-3/omega-6 fats for brain function. Use zero calorie foods as the base of meals, then add lean protein (chicken, fish, tofu) and small amounts of healthy fats. Think 60-70% vegetables by volume, 20-30% protein, 10% fats.

Are there any zero calorie foods that taste good without seasoning?

Cucumber, sugar snap peas, cherry tomatoes (20 calories per 100g), and bell peppers have natural sweetness that makes them enjoyable raw. Most people find these more palatable plain compared to leafy greens or celery. The crunch factor also makes them more satisfying as snacks. Keep pre-cut vegetables in your fridge for easy access throughout the day.

Next step: Fill half your plate with these low-calorie vegetables at every meal for 7 days—track how your hunger and energy levels change.