Understanding Gluten and the Gluten-Free Diet
Gluten is the name for a group of proteins naturally present in certain grains, especially wheat, barley, and rye.
In plants, these proteins help store energy that supports germination and early growth. In food production, gluten plays an important role in texture. It helps dough hold together, retain moisture, and rise by trapping air bubbles during baking.
For most people, gluten is not harmful. But for individuals with celiac disease, non-celiac gluten sensitivity, or gluten intolerance, eating gluten can trigger unwanted symptoms and health problems.
Following a gluten-free diet can be challenging because gluten often appears in processed foods under unfamiliar names. Knowing what to avoid—and what to choose instead—can make shopping and meal planning much easier.
Foods to Avoid on a Gluten-Free Diet
A gluten-free diet requires avoiding certain grains and any ingredients made from them.
Grains to Avoid
- Wheat
- Barley
- Rye
- Bulgur
- Kamut
- Triticale
- Couscous
Wheat and Grain-Based Ingredients to Avoid
When reading labels, watch for these names. Some are alternate grain varieties, while others are additives commonly used in packaged foods.
- Malted barley flour
- Malted milk
- Malt syrup
- Barley malt extract
- Malt vinegar
- Malt flavoring
- Wheat berries
- Emmer
- Durum
- Semolina
- Farina
- Spelt
- Graham
- Farro
- Einkorn
- Brewer’s yeast
- Wheat starch
Processed Products That Often Contain Gluten
Many everyday packaged foods contain hidden gluten. Common examples include:
- Pasta
- Wheat flour
- Cakes
- Wheat protein
- Bread
- Crackers
- Pretzels
- Malt beverages
- Beer
- Breakfast cereals
- Desserts
- Baked goods
- Many snack foods
Fortunately, gluten-free versions of many of these products are now widely available.
More Than 100 Naturally Gluten-Free Foods
Although the gluten-free diet excludes several grains, there are still many naturally gluten-free foods to enjoy.
However, cross-contamination can still be a concern. Even naturally gluten-free foods may cause problems if they are processed in facilities that also handle wheat, barley, or rye.
The term “gluten-free” on food packaging is regulated by the FDA, so it is generally reliable. When in doubt, choose products clearly labeled gluten-free.
It is also helpful to review the allergen statement on the packaging. Look for the word “Contains” followed by wheat. While this is mainly designed for people with wheat allergies, it can still help identify foods that should be avoided.
Below is a practical gluten-free food list, along with items that require extra caution.
Naturally Gluten-Free Grains
These grains and grain-like foods are naturally free of gluten:
- Oats
- Quinoa
- White rice
- Brown rice
- Buckwheat
- Amaranth
- Millet
- Teff
- Sorghum
Grain Products to Watch Carefully
- Oats are naturally gluten-free, but they are often contaminated during harvesting or processing.
- Only buy oats that are specifically labeled gluten-free.
Vegetables
Fresh vegetables are naturally gluten-free and provide fiber, vitamins, and minerals that support overall health.
- Potatoes
- Green beans
- Potato starch
- Potato flour
- Kale
- Cassava
- Arrowroot
- Pumpkin
- Tapioca
- Zucchini
- Bok choy
- Bell peppers
- Sweet potatoes
- Cauliflower
- Carrots
- Leafy greens
- Squash
- Corn
- Popcorn
- Broccoli
- Cabbage
- Spinach
- Peas
- Fresh herbs such as basil and parsley
- Garlic
Vegetable Products to Watch Out For
Fresh vegetables are one of the safest foods on a gluten-free diet. Plain canned and frozen vegetables are often safe as well, but it is still smart to check the label.
Avoid canned or frozen vegetables with:
- Added sauces
- Seasonings
- Flavorings
Unless the package clearly states that the product is gluten-free, it is better to avoid it.
Fruits
Fresh fruit is another naturally gluten-free staple.
- Apples
- Olives
- Grapes
- Pineapple
- Bananas
Fruit Products to Watch Out For
Plain fresh, frozen, and canned fruits are generally safe. Still, caution is needed with processed fruit products.
Be careful with:
- Frozen fruit with sauces or flavorings
- Canned fruit with added ingredients
- Dried fruit that may be contaminated during processing
Choose dried fruit labeled gluten-free whenever possible.
Fruit spreads are usually made from fruit, sugar, and pectin, which is naturally gluten-free. Even so, always read the ingredients list to make sure no wheat-based additives are included.
If you are unsure, check the allergen statement for wheat.
Animal Proteins
Fresh meat, seafood, poultry, and eggs are naturally gluten-free and are suitable for people with celiac disease or gluten sensitivity.
Seafood and Fish
- Salmon
- Tuna
- Shrimp
- Lobster
- Scallops
- Shellfish
- Mollusks
Red Meat
- Beef
- Pork
- Bison
- Lamb
Poultry
- Turkey
- Chicken
- Duck
Animal Proteins to Watch Out For
Not all protein foods are easy to evaluate, especially when they are sold without full packaging.
Use caution with:
- Deli meats
- Hot dogs
- Sausages
- Pepperoni
- Salami
- Liverwurst
- Breaded meats
- Microwave meals with meat
These products may contain wheat-based fillers, binders, or thickeners. If there is no clear label, ask for ingredient information before buying.
Plant-Based Proteins
Many vegetarian and vegan protein sources can fit into a gluten-free eating plan.
Soy-Based Proteins and Meat Alternatives
- Tofu
- Edamame
- Tempeh
Legumes
- Chickpeas
- Lentils
- Peanuts
- Kidney beans
Nuts and Nut Milks
- Walnuts
- Almonds
- Cashews
- Almond milk
- Coconut milk
- Soy milk
Seeds
- Hemp seeds
- Chia seeds
- Pumpkin seeds
- Sunflower seeds
- Flaxseed
Plant Proteins to Watch Out For
- Avoid seitan, which is made from wheat gluten.
- Check vegetarian meat substitutes carefully, as some contain soy sauce or other hidden gluten ingredients.
If a plant-based product is processed or flavored, always read the label before buying.
Dairy Products
Most plain dairy foods are naturally free of gluten.
- Plain yogurt
- Milk
- Cheese
- Cottage cheese
- Sour cream
Dairy Products to Watch Out For
Some dairy products may contain gluten-containing additives.
Be cautious with:
- Malted milk drinks
- Flavored yogurt
- Flavored milk
- Ice cream with added flavorings or thickeners
Always review the ingredient label if the product is flavored, sweetened, or processed.
Condiments
Some condiments are often gluten-free, but labels should still be checked.
- Tamari
- Mustard
- Ketchup
- Mayonnaise
- Vinegar
Sauces and Condiments to Watch Out For
Traditional soy sauce usually contains wheat and should be avoided on a gluten-free diet.
Tamari is often gluten-free, but not always, so confirm by reading the package.
Also watch for modified food starch. It is commonly made from corn, but in some cases it may come from wheat. If you see this ingredient in a sauce or condiment, check whether the allergen statement says the product contains wheat.
Single-ingredient spices are usually safe. However, spice blends may include gluten-containing additives such as:
- Wheat flour
- Hydrolyzed wheat protein
- Malt ingredients
Final Thoughts
A gluten-free diet means avoiding wheat, barley, rye, and products made from them. While that may seem restrictive at first, there are still many naturally gluten-free foods to choose from, including grains, vegetables, fruit, protein foods, dairy, nuts, seeds, and legumes.
The key to success is learning how to spot hidden gluten in processed foods, checking ingredient labels carefully, and choosing products marked gluten-free whenever possible.
