Onion vs Sweet Potato: 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?
Both foods have similar nutritional profiles
Both foods have similar nutritional profiles with each winning in different categories. Your choice should depend on your specific dietary goals and preferences. Onion has 40 calories while Sweet Potato has 86 calories per 100g.
Quick Summary
Fewer Calories
Onion
40 kcal
More Protein
Sweet Potato
1.6g
More Fiber
Sweet Potato
3g
Less Sugar
Onion
4.2g
Visual Comparison
Side-by-Side Nutrition Table
| Nutrient | Onion | Sweet Potato | Difference |
|---|---|---|---|
| Calories | 40kcal✓ | 86kcal | -46.0kcal |
| Protein | 1.1g | 1.6g✓ | -0.5g |
| Carbohydrates | 9g✓ | 20g | -11.0g |
| Fat | 0.1g | 0.1g | 0.0g |
| Fiber | 1.7g | 3g✓ | -1.3g |
| Sugar | 4.2g | 4.2g | 0.0g |
| Sodium | 4mg✓ | 55mg | -51.0mg |
Serving Size Comparison
All values above are per 100g. Here's how they compare in common serving sizes:
Onion
Sweet Potato
Diet Compatibility
Onion
Sweet Potato
When to Choose Onion
- ✓Lower in calories (40 vs 86)
- ✓Lower in carbs (9g vs 20g)
- ✓Less sugar (4.2g vs 4.2g)
- ✓Lower sodium (4mg vs 55mg)
Common Uses
When to Choose Sweet Potato
- ✓Higher in protein (1.6g vs 1.1g)
- ✓More fiber (3g vs 1.7g)
Common Uses
Onion vs Sweet Potato: Nutritional Analysis
Sweet Potato is more calorie-dense at 86 calories per 100g compared to 40 for Onion, a difference of 46 calories. On the protein front, Sweet Potato delivers more with 1.6g 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 Sweet Potato tell different nutritional stories. Onion provides 9g of carbohydrates, 0.1g of fat, and 1.7g of fiber per 100g, while Sweet Potato contains 20g carbs, 0.1g fat, and 3g fiber. The higher fiber content in Sweet Potato supports digestive health, helps regulate blood sugar after meals, and contributes to longer-lasting satiety.
Key Takeaways
- For weight management: Onion is the lower-calorie choice at 40 cal/100g, making it more suitable for calorie-controlled diets.
- For muscle building: Sweet Potato provides more protein (1.6g/100g), supporting muscle repair and growth.
- For sustained energy: Sweet Potato offers more fiber (3g/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 Sweet Potato?
Sweet Potato has more calories with 86 kcal per 100g, compared to Onion with 40 kcal. That's a difference of 46 calories per 100g serving.
Is Onion healthier than Sweet Potato?
Onion and Sweet Potato have similar nutritional profiles, with each food winning in different categories. The healthier choice depends on your specific dietary goals and nutritional needs.
What is the protein difference between Onion and Sweet Potato?
Sweet Potato has more protein with 1.6g per 100g, compared to Onion with 1.1g. Sweet Potato provides 0.5g more protein per 100g serving.
Which is better for weight loss, Onion or Sweet Potato?
For weight loss, Onion is the better choice with only 40 calories per 100g compared to 86 calories in Sweet Potato. Sweet Potato also offers 3g of fiber per 100g, which helps you feel fuller longer.
Does Onion or Sweet Potato have fewer carbs?
Onion has fewer carbs with 9g per 100g, compared to Sweet Potato with 20g. If you're following a low-carb diet, Onion is the better option with 11.0g 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.