Which has more calories, onion or spinach?

Per 100 g, onion has 40 calories and spinach has 23. Spinach is lower in calories.

Which has more protein, onion or spinach?

Onion has 1.1 g of protein per 100 g; spinach has 2.9 g. Spinach wins on protein.

Is onion or spinach better for weight loss?

For a calorie deficit, the lower-calorie, higher-protein option usually helps you stay full on fewer calories. Here that leans toward spinach — but portion size matters more than which food you pick.

Calorie comparison

Onion vs Spinach

Per 100 grams, spinach is the lighter choice by 17 calories, while spinach delivers more protein. The right pick depends on your goal — fewer calories for a cut, more protein to stay full.

Onion nutrition →Spinach nutrition →

Per 100 grams

Per 100 g	Onion	Spinach
Calories	40	23
Protein	1.1 g	2.9 g
Carbs	9 g	3.6 g
Fat	0.1 g	0.4 g

Orange highlights the "better for a calorie deficit" value (fewer calories, fat and carbs; more protein). Your goals decide what "better" means.

Per typical serving

🧅 Onion

1 medium (110 g)

44 cal

1.2 g protein · 9.9 g carbs · 0.1 g fat

🥬 Spinach

1 cup (30 g)

7 cal

0.9 g protein · 1.1 g carbs · 0.1 g fat

Frequently asked

Which has more calories, onion or spinach?
Per 100 g, onion has 40 calories and spinach has 23. Spinach is lower in calories.
Which has more protein, onion or spinach?
Onion has 1.1 g of protein per 100 g; spinach has 2.9 g. Spinach wins on protein.
Is onion or spinach better for weight loss?
For a calorie deficit, the lower-calorie, higher-protein option usually helps you stay full on fewer calories. Here that leans toward spinach — but portion size matters more than which food you pick.

More comparisons

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