Short answer: Yes — lettuce is low FODMAP in generous serving sizes across every common variety. According to the Monash University FODMAP Program, lettuce is one of the easiest salad bases to tolerate on the elimination phase of a low-FODMAP diet.
This makes lettuce a reliable staple if you have IBS, SIBO, or are working through the FODMAP elimination phase.
Low FODMAP Serving Sizes by Variety
| Lettuce Variety | Low-FODMAP Serving | Notes |
|---|---|---|
| Iceberg lettuce | 2 cups (75 g) | Fully low FODMAP, no upper limit tested to trigger |
| Romaine (cos) | 2 cups (75 g) | Safe in large amounts |
| Butter (Boston) lettuce | 1 cup (35 g) | Low FODMAP at typical salad portions |
| Red-leaf lettuce | 1 cup (35 g) | Safe; avoid pairing with high-FODMAP dressings |
| Rocket / arugula | 1 cup (25 g) | Low FODMAP; peppery flavor holds up to lemon-EVOO |
| Radicchio | 1/2 cup (18 g) | Low FODMAP in small serves — has some fructans at large amounts |
All amounts above are within Monash tested green-light thresholds. Portion still matters if you stack multiple green-light foods together — see our FODMAP stacking guide for context.
Why Lettuce Is Safe
Lettuce is 95% water with negligible fructans, GOS, or polyols in typical salad portions. The leafy structure means you naturally eat it in moderate volumes — unlike garlic or onion, there is no concentrated FODMAP load per bite.
Building an IBS-Friendly Salad
Start with a lettuce base (romaine or butter are the most nutrient-dense) and layer:
- Protein: grilled chicken, hard-boiled eggs, canned tuna, firm tofu (all low FODMAP)
- Low-FODMAP veg: cucumber, cherry tomatoes (≤5), carrots, red bell pepper (≤43g), radish
- Fats: olive oil, garlic-infused oil, walnuts (10 halves), pumpkin seeds (2 tbsp)
- Skip: croutons with onion/garlic, honey-mustard dressings, avocado over 30 g, and creamy dressings with added inulin
Use our FODMAP Food Checker to verify any add-in before serving.
What to Avoid
- Bagged salad kits — most contain hidden garlic or onion powder in dressings or croutons
- Restaurant Caesar dressing — usually contains garlic and anchovy paste with onion
- Coleslaw mixes — often contain cabbage in high volume plus onion in the dressing
The Bottom Line
Lettuce is one of the safest low-FODMAP foods on your plate. Fill your bowl freely with iceberg or romaine, watch the dressing, and pair with tested low-FODMAP proteins and vegetables.
Want a ready-made low-FODMAP salad meal? Try our Low FODMAP Burrito Bowl or convert any salad you love with the Recipe Converter.
This article is for informational purposes only and is not a substitute for medical advice. Consult a registered dietitian before starting a low-FODMAP diet.