Eating out · Hot subs
Low FODMAP at Firehouse Subs
Firehouse Subs is workable if you build carefully: the steamed meats themselves are mostly simple, and most US locations will swap any medium sub onto a gluten-free roll. The traps are everywhere else — every sub comes "Fully Involved" with raw onion by default, honey ham anchors several signature subs, and the popular sauces (Italian dressing, peppercorn ranch, marinara, BBQ) lean on garlic, onion, honey, or high-fructose corn syrup.
✅ Safest picks
Smoked Turkey Breast Sub (medium, on gluten-free roll)
Plain smoked turkey with lettuce, tomato, mayo and deli mustard avoids onion, garlic, honey ham and — on the Schar roll — wheat fructans.
💬 Order it: Ask for the gluten-free roll (medium only, small upcharge), say 'no onion', and stick to mayo and yellow deli mustard — skip Italian dressing.
Firehouse Salad with Grilled Chicken
Romaine, cucumber, tomato, green bell pepper and grilled chicken is a naturally low-FODMAP base with no bread at all.
💬 Order it: Skip ranch, Italian and honey mustard; ask for balsamic vinaigrette on the side and use a light drizzle, or just oil and vinegar. Hold the onion if offered.
Turkey Bacon Ranch (no ranch, no onion, on gluten-free roll)
With the peppercorn ranch removed it becomes a turkey, bacon and sharp cheddar sub — no garlic-onion dressing and no lactose-heavy sauce.
💬 Order it: Order 'no ranch, no onion', add mayo or mustard instead, and swap to the gluten-free roll; hard cheddar itself is very low in lactose.
Firehouse Steak & Cheese (no onions, on gluten-free roll)
The griddled steak, provolone and green bell peppers are fine once you pull the sautéed onions and the wheat roll.
💬 Order it: Say 'no onions' explicitly — they are mixed in by default — and keep mayo/mustard as your only condiments.
Lay's Kettle Cooked Original chips + dill pickle spear
Plain potato chips and a brine-preserved pickle spear are both low-FODMAP sides with no onion or garlic seasoning.
💬 Order it: Stick to the plain/original chip flavor — sour cream & onion, BBQ and cheddar varieties carry onion, garlic or lactose powders.
⚠️ Skip these
Good to know
- •Every sub is served 'Fully Involved' — lettuce, tomato, onion, mayo, mustard — so always say 'no onion' when ordering.
- •Any medium sub can go on the Schar gluten-free roll (corn/rice based, most US locations, small upcharge), which removes the wheat-roll fructan load in one move.
- •Treat sauces as the main hazard: Italian dressing, peppercorn ranch, honey mustard, marinara and the BBQ brisket sauce all carry garlic, onion, honey or HFCS — mayo and plain yellow deli mustard are the safe condiments.
- •Virginia honey ham hides in many combo subs (Hook & Ladder, Club on a Sub, Firehouse Hero) — ask to swap it for extra smoked turkey.
- •The famous free hot-sauce bar is mostly garlic-based hot sauces — skip it or bring your own bottle.
- •Portions run big: a medium is plenty, and any sub can be made as a chopped salad instead of on bread if you want to drop the roll entirely.
At a different restaurant? Photograph any menu and get every dish ranked in seconds.
Scan a menu — freeMenus and recipes change; scores reflect typical preparations and published FODMAP research. Informational only — not medical advice. Always confirm ingredients with restaurant staff.