Mushroom vs Onion: Nutrition Comparison
Which is healthier? Compare calories, protein, carbs, and more
Complete side-by-side nutrition comparison per 100g serving | Updated 2026
Which is Healthier?
Mushroom is generally healthier
Mushroom comes out ahead in this comparison, winning in 3 out of 5 key nutritional categories. It has fewer calories (22 vs 40), more protein (3.1g vs 1.1g), less sugar (0.1g vs 4.2g), making it the better choice for most health goals.
Quick Summary
Fewer Calories
Mushroom
22 kcal
More Protein
Mushroom
3.1g
More Fiber
Onion
1.7g
Less Sugar
Mushroom
0.1g
Visual Comparison
Side-by-Side Nutrition Table
Serving Size Comparison
All values above are per 100g. Here's how they compare in common serving sizes:
Mushroom
Onion
Diet Compatibility
Mushroom
Onion
When to Choose Mushroom
- ✓Lower in calories (22 vs 40)
- ✓Higher in protein (3.1g vs 1.1g)
- ✓Lower in carbs (3.3g vs 9g)
- ✓Less sugar (0.1g vs 4.2g)
Common Uses
When to Choose Onion
- ✓More fiber (1.7g vs 1g)
- ✓Lower sodium (4mg vs 5mg)
Common Uses
Mushroom vs Onion: Nutritional Analysis
Onion is more calorie-dense at 40 calories per 100g compared to 22 for Mushroom, a difference of 18 calories. On the protein front, Mushroom delivers more with 3.1g per 100g versus 1.1g, which matters for muscle maintenance, satiety, and overall metabolic health. These differences become meaningful when you consider how each food fits into your daily dietary pattern rather than looking at any single nutrient in isolation.
Macronutrient Breakdown
The macronutrient profiles of Mushroom and Onion tell different nutritional stories. Mushroom provides 3.3g of carbohydrates, 0.3g of fat, and 1g of fiber per 100g, while Onion contains 9g carbs, 0.1g fat, and 1.7g fiber. The higher fiber content in Onion supports digestive health, helps regulate blood sugar after meals, and contributes to longer-lasting satiety. Sugar content also differs: Mushroom contains 0.1g while Onion has 4.2g per 100g. Lower sugar options are generally preferable for blood sugar management and dental health.
Key Takeaways
- For weight management: Mushroom is the lower-calorie choice at 22 cal/100g, making it more suitable for calorie-controlled diets.
- For muscle building: Mushroom provides more protein (3.1g/100g), supporting muscle repair and growth.
- For sustained energy: Onion offers more fiber (1.7g/100g), which slows digestion and provides steadier energy release.
- Overall: Neither food is universally "better" than the other. The right choice depends on your specific nutritional goals, meal context, and dietary preferences. Both can play a role in a balanced diet.
Frequently Asked Questions
Which has more calories, Mushroom or Onion?
Onion has more calories with 40 kcal per 100g, compared to Mushroom with 22 kcal. That's a difference of 18 calories per 100g serving.
Is Mushroom healthier than Onion?
Based on our nutritional analysis, Mushroom is generally the healthier choice, winning in 3 out of 5 key nutritional categories. Mushroom has 22 calories, 3.1g protein, and 1g fiber per 100g. However, the best choice depends on your specific dietary goals.
What is the protein difference between Mushroom and Onion?
Mushroom has more protein with 3.1g per 100g, compared to Onion with 1.1g. Mushroom provides 2.0g more protein per 100g serving.
Which is better for weight loss, Mushroom or Onion?
For weight loss, Mushroom is the better choice with only 22 calories per 100g compared to 40 calories in Onion. Onion also offers 1.7g of fiber per 100g, which helps you feel fuller longer.
Does Mushroom or Onion have fewer carbs?
Mushroom has fewer carbs with 3.3g per 100g, compared to Onion with 9g. If you're following a low-carb diet, Mushroom is the better option with 5.7g fewer carbohydrates.
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About Our Data
All nutrition data in this comparison is sourced from the USDA FoodData Central, the official food composition database maintained by the U.S. Department of Agriculture. Values are based on 100g servings for accurate comparison.
Health Disclaimer: This comparison is for informational purposes only and is not intended as medical or dietary advice. Nutritional needs vary by individual. The best food choice depends on your personal health goals, dietary requirements, and preferences. Consult a healthcare provider or registered dietitian for personalized nutrition guidance.