Plain string cheese is low FODMAP. A standard stick of mozzarella string cheese contains well under the 1 gram of lactose per serving that defines the low FODMAP threshold, making it a safe snack for most people following the elimination phase of a low FODMAP diet.
Why Mozzarella Is Naturally Low in Lactose
Lactose is the main FODMAP concern in dairy products, but not all cheeses contain meaningful amounts of it. Mozzarella, the cheese used in virtually all string cheese, loses most of its lactose during production. Since lactose dissolves in water, the whey draining step pulls the bulk of it out of the curd. Any lactose that remains gets further reduced when the curd is washed, a common step in mozzarella production. Washing the curd even twice can remove enough lactose and organic acids that they become nearly undetectable in the finished cheese.
The result is a cheese that starts with milk (high in lactose) but ends up with very little. This is why aged and processed cheeses tend to be better tolerated than soft, fresh dairy products like ricotta or cottage cheese, which retain more whey and therefore more lactose.
How String Cheese Fits the FODMAP Threshold
Monash University, the research group behind the low FODMAP diet, sets the cutoff at less than 1 gram of lactose per serving for a food to qualify as low FODMAP. A typical string cheese stick weighs about 28 grams and contains a small fraction of a gram of lactose. That puts it comfortably within the safe range.
One stick is a standard serving. Eating two or three at once increases your lactose load, and while you’d likely still be under the threshold, stacking servings of multiple lactose-containing foods in the same meal can push your total intake higher than expected. If you’re in the elimination phase, sticking to one stick per sitting is the safest approach.
What to Look For on the Label
A basic string cheese ingredient list is short: pasteurized part-skim milk, cheese culture, salt, and enzymes. That combination contains no moderate or high FODMAP ingredients. The cultures and enzymes actually help break down any residual lactose during production, which works in your favor.
The trouble starts with flavored varieties. Some brands sell string cheese with added garlic powder, onion powder, or seasoning blends. Both garlic and onion are among the highest FODMAP foods, and even small amounts in powder form can trigger symptoms. If you see either ingredient listed, skip that variety. Other potential additions to watch for include whey protein concentrate (reintroduces lactose), honey, and certain fruit or vegetable seasonings.
Some brands now sell string cheese specifically labeled “lactose free,” made by adding lactase enzyme to break down any remaining lactose. These are perfectly fine on a low FODMAP diet, though standard mozzarella string cheese is already low enough in lactose that the lactose-free version isn’t strictly necessary.
Other Low FODMAP Cheese Options
If you enjoy string cheese, you’ll likely tolerate other firm and aged cheeses as well. The general rule: the harder and more aged the cheese, the less lactose it contains.
- Cheddar: Aged cheddar contains trace amounts of lactose, often less than 0.1 grams per serving.
- Swiss and Parmesan: Both are very low in lactose due to long aging periods that allow bacteria to consume residual sugars.
- Brie and Camembert: These soft cheeses are low FODMAP in small portions (around 40 grams), though they contain slightly more lactose than harder varieties.
- Cream cheese: Low FODMAP at about 2 tablespoons per serving, but the lactose content rises quickly with larger amounts.
Cheeses to be more cautious with include ricotta, cottage cheese, and halloumi, all of which retain more whey and therefore more lactose per serving. They aren’t necessarily off-limits, but portion sizes matter more with these varieties.
Practical Tips for Snacking
String cheese is one of the most convenient low FODMAP snacks because it’s portable, doesn’t need refrigeration for a few hours, and pairs well with other safe foods. Combine it with a small handful of walnuts, a few rice crackers, or some grapes for a balanced snack that covers protein, fat, and carbohydrates without stacking FODMAP triggers.
If you’re reintroducing lactose during the challenge phase of the diet, string cheese isn’t the best test food because its lactose content is so low. You’d need a higher lactose source like milk or yogurt to meaningfully assess your tolerance. String cheese works better as a reliable safe food you keep in rotation while you test other categories.