Lettuce is one of the lowest-carb foods you can eat. A cup of shredded iceberg lettuce contains just 2.1 grams of total carbohydrates, and after subtracting fiber, the net carbs drop to roughly 1.3 grams. No matter which variety you choose, lettuce is about as close to zero-carb as a whole food gets.
Carbs by Lettuce Variety
Water makes up over 95% of raw lettuce by weight, which is why the carbohydrate content is so minimal across every type. The differences between varieties come down to leaf density and how much fits into a standard cup.
For a one-cup shredded serving:
- Iceberg (72g): 2.1g total carbs, 0.9g fiber, roughly 1.2g net carbs
- Romaine (47g): 1.5g total carbs, 1.0g fiber, roughly 0.5g net carbs
- Butterhead/Boston/Bibb (55g): about 1.8g total carbs, 0.9g fiber
- Green leaf (36g): under 1g total carbs
- Red leaf (28g): under 1g total carbs
Red and green leaf lettuce weigh less per cup because the leaves are looser and fluffier, so the carb count per serving is even smaller. Even if you pile three or four cups into a big salad bowl, you’re still looking at well under 10 grams of total carbs from the lettuce alone.
What About Sugar in Lettuce?
A cup of iceberg lettuce contains about 1.4 grams of natural sugar, which accounts for most of its carbohydrate content. The rest comes from fiber. These are not added sugars. They’re naturally occurring in the plant tissue and present in such small amounts that they have virtually no impact on blood sugar levels. The American Diabetes Association classifies all salad greens, including lettuce, romaine, spinach, arugula, and endive, as non-starchy vegetables, the category with the least effect on blood glucose.
How Lettuce Compares to Other Greens
If you’re choosing between salad greens for a low-carb diet, the differences are tiny. Per one-cup raw serving, romaine has about 0.5 grams of net carbs, spinach has 0.4 grams, and kale has just 0.05 grams. In practical terms, these numbers are all so low that none of them will meaningfully affect your daily carb budget.
Where greens differ more noticeably is in nutrients like vitamin A, vitamin K, and folate. Romaine and leaf lettuces are considerably more nutrient-dense than iceberg, which is mostly water and crunch. If you’re already eating low-carb and want to get the most nutrition from your greens, darker varieties like romaine, spinach, or kale offer more per bite without any real carb penalty.
Lettuce on a Keto or Low-Carb Diet
Most ketogenic diets aim for 20 to 50 grams of net carbs per day. A generous salad with three cups of romaine comes in at roughly 1.5 grams of net carbs, which is a negligible fraction of even the strictest daily limit. This is why lettuce is treated as essentially “free” on nearly every low-carb plan.
Lettuce also works well as a bread substitute. A large butterhead leaf holds about 0.2 grams of net carbs, so wrapping a burger or sandwich filling in lettuce instead of a bun saves you 20 to 30 grams of carbs per meal. Two or three leaves still add less than a single gram.
The place where carbs sneak in is everything you put on top of the lettuce. Croutons, sweetened dressings, dried fruit, and candied nuts can easily push a salad into the 30-to-50-gram range. The lettuce itself is rarely the problem.