Source: USDA FoodData Central · Raw · Data verified by CaloriesCalc
* % Daily Value based on a 2,000 kcal diet.
| Nutrient | Amount | % Daily Value | Bar |
|---|---|---|---|
| Vitamin K | 102.5 µg | 85% | |
| Vitamin A (RAE) | 436 µg | 48% | |
| Folate (B9) | 136 µg | 34% | |
| Vitamin C | 9.2 mg | 10% | |
| Potassium | 194 mg | 4% | |
| Vitamin B6 | 0.09 mg | 5% | |
| Magnesium | 13 mg | 3% | |
| Calcium | 33 mg | 3% | |
| Phosphorus | 30 mg | 2% | |
| Iron | 0.97 mg | 5% |
| Weight | Calories | Carbs | Protein | Fat |
|---|
| Serving | Weight | Calories | Carbs | Net Carbs | Fat |
|---|---|---|---|---|---|
| ⭐ 1 cup shredded | 72g | 11 kcal | 2.1g | 1.1g | 0.2g |
| 1 large leaf | 28g | 4 kcal | 0.8g | 0.4g | 0.1g |
| 1 head romaine | 141g | 21 kcal | 4.1g | 2.3g | 0.3g |
| 1 head iceberg | 539g | 81 kcal | 15.5g | 8.7g | 1.2g |
| 1 oz | 28g | 4 kcal | 0.8g | 0.4g | 0.1g |
Romaine lettuce is 95% water. Net carbs are 1.6g per 100g — one of the lowest of any food. Different varieties vary significantly: romaine and red leaf lettuce are far more nutritious than iceberg lettuce.
Not all lettuce is equal. Romaine lettuce is dramatically more nutritious than iceberg: it contains 8× more vitamin A, 4× more vitamin K, 3× more vitamin C, and 2× more folate and iron. Iceberg lettuce is 96% water with minimal nutrients — essentially crunchy water. For maximum nutritional benefit, choose romaine, red leaf, green leaf, or butterhead lettuce over iceberg. The darker the green, the more nutrients.
Wild lettuce has been used as a sedative for centuries. Cultivated lettuce still contains small amounts of lactucin and lactucopicrin — bitter compounds with mild sedative and analgesic (pain-relieving) properties. A 2017 study found lettuce extract had significant sedative effects in mice, reducing movement by 30%. While the amounts in a salad are small, some people report that large amounts of lettuce (particularly romaine) cause drowsiness — this is attributed to lactucin.
Romaine lettuce provides 103µg of vitamin K per 100g — 85% of the daily requirement. Vitamin K1 activates osteocalcin, which binds calcium into bone matrix, and also activates matrix Gla-protein (MGP), which may help reduce risk of calcium from depositing in blood vessels (arterial calcification). Low vitamin K intake is independently associated with osteoporosis and cardiovascular disease. Dark leafy lettuces are among the best dietary sources of this underconsumed vitamin.
At 15 kcal per 100g, lettuce is one of the lowest-calorie foods available. A large salad bowl (200g of romaine) has only 30 calories. The high water and fiber content creates gastric volume and triggers satiety signals before significant calories are consumed. Studies on high-volume, low-calorie eating (volumetrics approach) consistently show that starting meals with large salads reduces overall calorie intake by 100-200 kcal.
Nutrition values sourced from USDA FoodData Central. Not medical advice.