A cup of raw spinach contains just 7 calories, making it one of the lowest-calorie foods you can eat. Per 100 grams (about 3.5 ounces), raw spinach provides roughly 23 calories. That near-zero calorie count, combined with a surprisingly rich nutrient profile, is what makes spinach a staple in salads, smoothies, and cooked dishes alike.
Calories by Serving Size
The calorie count for spinach shifts dramatically depending on whether you’re eating it raw or cooked, because spinach wilts down to a fraction of its original volume when heated. Here’s how the numbers break down:
- 1 cup raw spinach (about 30g): 7 calories
- 100 grams raw spinach: 23 calories
- 1 cup cooked spinach (boiled, drained): 41 calories
That cooked cup isn’t higher in calories per leaf. It simply takes several cups of raw spinach to wilt down into one cup of cooked spinach. You’re eating roughly six times more spinach by weight in a cooked cup than in a raw one, which is why the calorie count appears to jump.
What Else Is in Those Calories
For 100 grams of raw spinach, you get 2.9 grams of protein, 3.6 grams of carbohydrates, and 2.2 grams of fiber. Subtract the fiber and you’re left with only 1.4 grams of net carbs. Fat is negligible at under half a gram. That protein number is notable for a vegetable. Gram for gram, spinach has more protein than many other greens.
Spinach also packs a dense concentration of micronutrients relative to its calorie count. A single raw cup delivers about 145 micrograms of vitamin K, which far exceeds the daily recommended intake. It’s also a strong source of vitamin A, iron, and calcium. Cleveland Clinic notes that spinach contains more fiber, protein, vitamin A, calcium, and iron than kale, though kale edges it out on vitamins K and C.
How Cooking Changes the Numbers
Boiling or steaming spinach doesn’t add calories on its own. A cup of plain boiled spinach, drained and unsalted, comes to about 41 calories. The real calorie shift happens when you add fat during cooking.
A typical serving of sautéed garlic spinach made with two tablespoons of olive oil comes to around 102 calories. The fat from the oil accounts for about 58% of those calories, turning a nearly calorie-free vegetable into something closer to a standard side dish. That’s not a bad thing. Fat helps your body absorb the fat-soluble vitamins in spinach, particularly vitamins A and K. But if you’re tracking calories closely, be aware that the spinach itself isn’t the variable. It’s what you cook it in.
For a lighter sautéed version, cutting the oil to one teaspoon or using a quick spray of cooking oil can keep the total well under 50 calories per serving while still giving you that wilted texture.
Spinach and Appetite Control
Beyond being low in calories, spinach may actively help you eat less. Spinach contains compounds called thylakoids, which are found in the membranes of green plant cells. A study published in the journal Appetite tested thylakoid-rich spinach extract in overweight women and found meaningful effects on hunger. Compared to a placebo, the spinach extract reduced hunger by 21%, increased feelings of fullness by 14%, and cut cravings for sweets and snacks by 36%. Cravings for salty snacks dropped by 30%.
These effects were linked to increased release of a satiety hormone called GLP-1, which plays a role in both fullness signaling and reward pathways in the brain. The strongest effects showed up in participants who scored higher for emotional eating, suggesting thylakoids may be especially useful for people who tend to snack in response to stress or cravings rather than physical hunger.
How Spinach Compares to Other Greens
All leafy greens are low-calorie, but spinach sits near the bottom of the range. Kale is slightly higher in calories per cup, though still minimal. Arugula and lettuce varieties fall in a similar range to spinach. The real difference between these greens isn’t calories. It’s nutrient density and flavor.
Spinach stands out for its iron and calcium content, its mild flavor that blends easily into smoothies and cooked dishes, and its high protein-to-calorie ratio. If you’re choosing between greens for a salad or a stir-fry, the calorie difference is essentially irrelevant. Pick based on taste, texture, and which nutrients you want more of. Mixing different greens gives you the broadest nutritional coverage.