Onion vs Zucchini: 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?
Zucchini is generally healthier
Zucchini comes out ahead in this comparison, winning in 3 out of 5 key nutritional categories. It has fewer calories (21 vs 40), more protein (1.5g vs 1.1g), less sugar (1.2g vs 4.2g), making it the better choice for most health goals.
Quick Summary
Fewer Calories
Zucchini
21 kcal
More Protein
Zucchini
1.5g
More Fiber
Onion
1.7g
Less Sugar
Zucchini
1.2g
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:
Onion
Zucchini
Diet Compatibility
Onion
Zucchini
When to Choose Onion
- ✓More fiber (1.7g vs 1g)
- ✓Lower sodium (4mg vs 10mg)
Common Uses
When to Choose Zucchini
- ✓Lower in calories (21 vs 40)
- ✓Higher in protein (1.5g vs 1.1g)
- ✓Lower in carbs (4g vs 9g)
- ✓Less sugar (1.2g vs 4.2g)
Common Uses
Onion vs Zucchini: Nutritional Analysis
Onion is more calorie-dense at 40 calories per 100g compared to 21 for Zucchini, a difference of 19 calories. On the protein front, Zucchini delivers more with 1.5g 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 Onion and Zucchini tell different nutritional stories. Onion provides 9g of carbohydrates, 0.1g of fat, and 1.7g of fiber per 100g, while Zucchini contains 4g carbs, 0.4g fat, and 1g 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: Onion contains 4.2g while Zucchini has 1.2g per 100g. Lower sugar options are generally preferable for blood sugar management and dental health.
Key Takeaways
- For weight management: Zucchini is the lower-calorie choice at 21 cal/100g, making it more suitable for calorie-controlled diets.
- For muscle building: Zucchini provides more protein (1.5g/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, Onion or Zucchini?
Onion has more calories with 40 kcal per 100g, compared to Zucchini with 21 kcal. That's a difference of 19 calories per 100g serving.
Is Onion healthier than Zucchini?
Based on our nutritional analysis, Zucchini is generally the healthier choice, winning in 3 out of 5 key nutritional categories. Zucchini has 21 calories, 1.5g protein, and 1g fiber per 100g. However, the best choice depends on your specific dietary goals.
What is the protein difference between Onion and Zucchini?
Zucchini has more protein with 1.5g per 100g, compared to Onion with 1.1g. Zucchini provides 0.4g more protein per 100g serving.
Which is better for weight loss, Onion or Zucchini?
For weight loss, Zucchini is the better choice with only 21 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 Onion or Zucchini have fewer carbs?
Zucchini has fewer carbs with 4g per 100g, compared to Onion with 9g. If you're following a low-carb diet, Zucchini is the better option with 5.0g 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.