First, let's take a look at the macros. Each of these are listed in grams and as usual, normalized to 200 calories for easy comparison, so we're always comparing apples to apples.
| Romaine lettuce | Watercress |
| Nutrient | romaine lettuce | watercress |
| Protein | 14g | 42g |
| Carbohydrate | 39g | 23g |
| Fiber | 25g | 9g |
| Fat | 4g | 2g |
| Monounsat. Fat | 0g | 2g |
| Polyunsat. Fat | 2g | 1g |
| Saturated Fat | 0g | 0g |
Next, let's take a look at the Vitamin density. These values are shown in units of percent of recommended daily intake. And since we're showing 200 calories worth, this means anything above 10% is good.
| Nutrient | romaine lettuce | watercress |
| Choline | 28% | 39% |
| Vitamin A | 821% | 465% |
| Vitamin C | 376% | 1042% |
| Vitamin E | 13% | 152% |
| Vitamin K | 1507% | 5682% |
Romaine lettuce have significantly more Vitamins A than watercress. Watercress have significantly more Vitamins E, C, K than romaine lettuce. Romaine lettuce are a good source of Niacin, Pantothenic Acid, Zinc. Romaine lettuce are a great source of Thiamin, Riboflavin, Vitamin B6, Potassium, Magnesium, Calcium, Phosphorus. Romaine lettuce are an excellent source of Vitamin A, Vitamin K, Vitamin C, Iron. Watercress are a good source of Niacin, Zinc. Watercress are a great source of Iron. Watercress are an excellent source of Vitamin A, Vitamin E, Vitamin K, Vitamin C, Thiamin, Riboflavin, Pantothenic Acid, Vitamin B6, Potassium, Magnesium, Calcium, Phosphorus.
And here we see the B-vitamins: B1 (Thiamin), B2 (Riboflavin), B3 (Niacin), B5 (Pantothenic Acid), B6 (Pyridoxine)
| Nutrient | romaine lettuce | watercress |
| Vitamin B1 | 85% | 164% |
| Vitamin B2 | 72% | 198% |
| Vitamin B3 | 31% | 30% |
| Vitamin B5 | 33% | 113% |
| Vitamin B6 | 79% | 213% |
| Vitamin B12 | 0% | 0% |
Now, lets look at mineral density. Here we have a lot of important electrolytes and minerals. Once again, units are in percent of RDI, thus for this 200 calorie serving anything above 10% would considered high.
| Nutrient | romaine lettuce | watercress |
| Sodium | 6% | 50% |
| Potasium | 83% | 171% |
| Calcium | 78% | 436% |
| Magnesium | 47% | 109% |
| Phosphorus | 61% | 188% |
| Iron | 190% | 61% |
| Manganese | 79% | 193% |
| Selenium | 10% | 36% |
| Copper | 56% | 140% |
| Zinc | 29% | 21% |