Top 9 Food Allergens: What Every Diner Needs to Know

The 9 major food allergens under US law are milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame. These account for roughly 90% of all food allergy reactions. Under FALCPA (2004) and the FASTER Act (2023), manufacturers must label these allergens. But at restaurants, there's no such labeling requirement, making it your job to identify them in every dish.

The FASTER Act and Sesame

For nearly two decades, US food labeling law recognized 8 major allergens. In April 2021, Congress passed the FASTER Act (Food Allergy Safety, Treatment, Education, and Research), adding sesame as the 9th. It took effect January 1, 2023. This was overdue. Sesame allergies had been rising for years, and sesame was already recognized as a major allergen by the EU, Canada, Australia, and many other countries. The US was behind. At restaurants, this means dishes with tahini, hummus, za'atar, sesame oil, and sesame seeds should be on your radar. For the full breakdown, see our sesame allergy restaurant guide.

1. Milk (Dairy)

Milk allergy is the most common food allergy in children. At restaurants, dairy hides everywhere: butter on grilled items, cream in soups and sauces, cheese in salads as a "garnish," casein in bread, whey in dressings, and lactose in seasoning blends. The trickiest source: many kitchens finish dishes with butter even when the menu doesn't mention it. A "grilled steak" may arrive butter-basted. Always ask. Full guide: Dairy-Free Dining.

2. Eggs

Eggs are in more restaurant dishes than most people realize. Fresh pasta (contains egg), egg wash on bread and pastries, mayo in dressings and sauces, tempura batter, meringue in desserts, and some broths clarified with egg whites. The sneakiest source: egg wash. Bread rolls, pretzels, and pastry crusts are often brushed with egg to create a glossy finish. The menu never mentions it. Full guide: Egg Allergy Restaurant Guide.

3. Fish

Fish hides in condiments more than in main dishes. Worcestershire sauce contains anchovies. Caesar dressing contains anchovies. Fish sauce is a base ingredient in Thai, Vietnamese, and some Chinese cooking. Surimi (imitation crab) is made from fish. Dashi stock in Japanese cuisine is fish-based. If you avoid fish, Asian cuisines are high-risk. Always ask whether sauces contain fish or fish derivatives. Full guide: Fish Allergy Restaurant Guide.

4. Crustacean Shellfish

Shrimp, crab, and lobster are the primary crustaceans. Shellfish proteins can survive in shared cooking oil, making cross-contamination a significant risk at seafood restaurants. Hidden sources: shrimp paste in Thai curries, crab in certain dips, lobster base in bisques and chowders. Glucosamine supplements are also shellfish-derived, though that's more relevant at home. Full guide: Shellfish Allergy Restaurant Guide.

5. Tree Nuts

Tree nuts include almonds, cashews, walnuts, pecans, pistachios, macadamias, Brazil nuts, and hazelnuts. At restaurants, they show up in pesto (pine nuts, sometimes walnuts), Asian stir-fries (cashews), desserts (almonds, hazelnuts), salad toppings, and mole sauce (various nuts). Critical: someone allergic to one tree nut may not be allergic to all of them, but many allergists recommend avoiding the entire category due to processing cross-contact. Full guide: Nut Allergy Playbook.

6. Peanuts

Peanuts are the most common cause of fatal food-related anaphylaxis. At restaurants, peanuts hide in satay sauce, many Asian stir-fries (peanut oil, ground peanuts), African and Caribbean dishes, some chili recipes, and desserts. Peanut oil is widely used for frying in some cuisines. Cold-pressed peanut oil retains allergenic proteins; highly refined peanut oil may not, but most allergists advise against relying on that distinction at restaurants. Full guide: Nut Allergy Playbook.

7. Wheat

Wheat is almost unavoidable in Western cooking without active effort. Bread, pasta, breading on fried foods, flour-thickened sauces (roux), many desserts, and surprisingly, soy sauce (which is brewed with wheat). Wheat allergy is distinct from celiac disease (autoimmune) and gluten intolerance (sensitivity). Someone with a wheat allergy may tolerate rye and barley, while someone with celiac cannot. Full guide: Gluten-Free Menu Scanner and Celiac Restaurant Guide.

8. Soybeans (Soy)

Soy sauce is the obvious source, but soy hides in many other places: soybean oil (used for frying in many restaurants), soy lecithin (in chocolate and baked goods), tofu, edamame, miso, tempeh, and some meat alternatives. Asian cuisines use soy heavily, making them higher-risk. But soy also appears in Western dishes through soybean oil and lecithin. Full guide: Soy Allergy Restaurant Guide.

9. Sesame

The newest addition to the major allergen list. Sesame appears in tahini (the base of hummus), sesame oil (a finishing oil in Asian cooking), sesame seeds on bread and sushi, za'atar spice blend, gomashio, halva, and some breadcrumbs. Middle Eastern and Asian cuisines use the most sesame. Bakeries have become higher-risk since sesame seeds are common toppings for bread, bagels, and burger buns. Full guide: Sesame Allergy Restaurant Guide.

Scanning for All 9 With AI

Tracking all 9 allergens across a restaurant menu is mentally exhausting. Menu Buddy handles it in one scan. Photograph the menu, and the AI checks every dish against all 9 allergens plus any custom allergens in your profile. The AI catches the hidden sources that menus don't list: wheat in soy sauce, anchovies in Caesar, sesame oil as a finishing drizzle, butter on grilled items. It won't catch everything a kitchen does behind the scenes, but it narrows your safe options dramatically before you even talk to your server.