Written by CalorieData Nutrition TeamReviewed by a Registered DietitianLast Updated: March 2026

Onion vs Chlorella: 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?

Chlorella is generally healthier

Chlorella comes out ahead in this comparison, winning in 3 out of 5 key nutritional categories. It has more protein (58g vs 1.1g), more fiber (5g vs 1.7g), less sugar (0g vs 4.2g), making it the better choice for most health goals.

Quick Summary

Fewer Calories

Onion

40 kcal

More Protein

Chlorella

58g

More Fiber

Chlorella

5g

Less Sugar

Chlorella

0g

Visual Comparison

Caloriesper 100g
Onion
40
Chlorella
340
Proteinper 100g
Onion
1.1g
Chlorella
58g
Carbohydratesper 100g
Onion
9g
Chlorella
9g
Fatper 100g
Onion
0.1g
Chlorella
6g

Side-by-Side Nutrition Table

NutrientOnionChlorellaDifference
Calories40kcal340kcal-300.0kcal
Protein1.1g58g-56.9g
Carbohydrates9g9g0.0g
Fat0.1g6g-5.9g
Fiber1.7g5g-3.3g
Sugar4.2g0g+4.2g
Sodium4mg200mg-196.0mg

Serving Size Comparison

All values above are per 100g. Here's how they compare in common serving sizes:

Onion

Per 100g:40 calories
Per cup (150g):60 calories
Per serving (85g):34 calories

Chlorella

Per 100g:340 calories
Per cup (150g):510 calories
Per serving (85g):289 calories

Diet Compatibility

Onion

Low-CarbLow-CalorieVeganVegetarianPaleoLow-Sodium

Chlorella

Low-CarbHigh-ProteinVeganVegetarianPaleoLow-Sodium

When to Choose Onion

  • Lower in calories (40 vs 340)
  • Lower in carbs (9g vs 9g)
  • Lower sodium (4mg vs 200mg)

Common Uses

SaladsStir-friesRoasted sidesSoups
View full Onion nutrition →

When to Choose Chlorella

  • Higher in protein (58g vs 1.1g)
  • More fiber (5g vs 1.7g)
  • Less sugar (0g vs 4.2g)

Common Uses

SaladsStir-friesRoasted sidesSoups
View full Chlorella nutrition →

Onion vs Chlorella: Nutritional Analysis

Chlorella is more calorie-dense at 340 calories per 100g compared to 40 for Onion, a difference of 300 calories. On the protein front, Chlorella delivers more with 58g 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 Chlorella tell different nutritional stories. Onion provides 9g of carbohydrates, 0.1g of fat, and 1.7g of fiber per 100g, while Chlorella contains 9g carbs, 6g fat, and 5g fiber. The higher fiber content in Chlorella supports digestive health, helps regulate blood sugar after meals, and contributes to longer-lasting satiety. Sugar content also differs: Onion contains 4.2g while Chlorella has 0g per 100g. Lower sugar options are generally preferable for blood sugar management and dental health.

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: Chlorella provides more protein (58g/100g), supporting muscle repair and growth.
  • For sustained energy: Chlorella offers more fiber (5g/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 Chlorella?

Chlorella has more calories with 340 kcal per 100g, compared to Onion with 40 kcal. That's a difference of 300 calories per 100g serving.

Is Onion healthier than Chlorella?

Based on our nutritional analysis, Chlorella is generally the healthier choice, winning in 3 out of 5 key nutritional categories. Chlorella has 340 calories, 58g protein, and 5g fiber per 100g. However, the best choice depends on your specific dietary goals.

What is the protein difference between Onion and Chlorella?

Chlorella has more protein with 58g per 100g, compared to Onion with 1.1g. Chlorella provides 56.9g more protein per 100g serving.

Which is better for weight loss, Onion or Chlorella?

For weight loss, Onion is the better choice with only 40 calories per 100g compared to 340 calories in Chlorella. Chlorella also offers 5g of fiber per 100g, which helps you feel fuller longer.

Does Onion or Chlorella have fewer carbs?

Onion and Chlorella have the same carbohydrate content at 9g per 100g.

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.