Most cheese contains very little sugar, and many aged varieties have virtually none. The sugar naturally present in cheese is lactose, a carbohydrate found in milk. During cheesemaking, bacteria consume most of that lactose and convert it into lactic acid, which is why a one-ounce serving of cheddar has just 0.07 grams of lactose and parmesan has essentially zero.
How Cheesemaking Removes Sugar
Milk starts with roughly 5% lactose by weight, which means a cup of whole milk contains about 12 grams of sugar. Cheese ends up with far less because of two things that happen during production: fermentation and whey drainage.
On the first day of cheesemaking, lactic acid bacteria ferment lactose into lactic acid. These bacteria are trapped inside the forming curd, where they steadily consume lactose. As they use up the lactose within the curd, more lactose from the surrounding liquid (whey) actually diffuses back in, only to be consumed as well. This continuous cycle means fermentation is remarkably efficient at breaking down sugar.
At the same time, draining the whey physically removes a large portion of the remaining lactose from the cheese. The combination of these two processes is why hard, aged cheeses can end up with sugar levels so low they round to zero on a nutrition label. Under FDA rules, any food with less than 0.5 grams of sugar per serving can legally list sugar as “0g,” which is why many cheese labels show no sugar at all even though trace amounts remain.
Sugar Content by Cheese Type
The general rule: the longer a cheese ages and the harder its texture, the less sugar it contains. Aging gives bacteria more time to consume residual lactose.
- Parmesan: 0 grams of lactose per ounce. Aged for months or years, it’s one of the lowest-sugar cheeses you can buy.
- Cheddar: 0.07 grams per ounce for sharp varieties. Even mild cheddar has only about 0.4 grams of carbs per slice.
- Goat cheese: 0 grams of carbs per ounce, despite goat’s milk having a similar lactose content to cow’s milk (4 to 5%).
- Blue cheese: 0.5 grams of carbs per slice (about 21 grams).
- Cream cheese: About 1 gram of carbs per ounce.
- Cottage cheese: 4.5 grams of carbs per half cup. Because it’s fresh and barely aged, much more lactose survives.
- Ricotta: Around 9 grams of carbs per half cup, making it one of the highest-sugar common cheeses.
Fresh, soft cheeses like ricotta and cottage cheese skip the long fermentation and aging steps, so they retain significantly more lactose. If you’re watching sugar intake for any reason, these are the ones to pay attention to.
Processed Cheese Is Different
Natural cheese gets its sugar only from whatever lactose survives fermentation. Processed cheese products can contain added sugars. Manufacturing may introduce ingredients like corn syrup or maltodextrin to improve flavor and texture. American cheese, for example, contains about 2 grams of carbs per slice, partly because of these additions.
Spray cheese and other heavily processed varieties also tend to land around 2 grams of carbs per ounce. If added sugar matters to you, check the ingredients list for terms like corn syrup, sugar, or maltodextrin rather than relying solely on the nutrition facts panel.
Cheese and Blood Sugar
Cheese has a very low glycemic index, meaning it causes minimal spikes in blood sugar. In fact, research on healthy volunteers found that eating cream cheese alongside a meal significantly reduced the peak blood sugar response compared to eating the same meal without it. The combination of fat, protein, and minimal carbohydrate in cheese slows digestion and blunts glucose absorption.
This is one reason cheese fits easily into low-carb and ketogenic diets. Most hard and semi-hard cheeses contribute fewer than 1 gram of carbs per serving, making them essentially negligible from a blood sugar perspective. Even for people managing diabetes, the sugar content of most natural cheese is too small to meaningfully affect glucose levels.
Lactose Intolerance and Cheese Sugar
People with lactose intolerance often avoid all dairy, but many cheeses are well tolerated precisely because so little lactose remains. Aged cheeses like parmesan, aged cheddar, and Swiss typically cause no symptoms because their lactose content is near zero. Goat and sheep milk cheeses aren’t inherently lower in lactose than cow’s milk versions (all three milks contain roughly 4 to 5% lactose), but aged versions of any of them lose most of that sugar during production.
Fresh cheeses are a different story. Ricotta and cottage cheese retain enough lactose to cause digestive discomfort in sensitive individuals. If you tolerate aged cheese but react to fresh varieties, that gap in lactose content is the reason.