Cheese is a staple food, but those following controlled carbohydrate diets, such as ketogenic or Atkins plans, often question its nutritional profile. Low-carb diets typically limit daily intake to 50–100 grams, while strict ketogenic plans require 20–50 grams per day. Most hard and aged cheeses are naturally very low in carbohydrates, making them compatible with these eating plans. However, carbohydrate content varies significantly between varieties, depending on how they are processed and aged.
Understanding Carbohydrates in Cheese
The carbohydrate content in cheese originates entirely from lactose, the natural sugar in milk. The process of turning milk into solid cheese naturally removes most of this sugar. When milk is curdled, the majority of the lactose remains in the liquid whey, which is separated and drained from the solid curds.
The small amount of lactose remaining in the curds is consumed by bacterial cultures. These cultures convert the residual lactose into lactic acid during fermentation and aging. This biological conversion is the primary reason why cheese contains minimal carbohydrates compared to its milk source.
The duration of the aging process directly determines the final carbohydrate content. Cheeses aged for many months or years allow bacteria more time to break down all traces of lactose. Therefore, older, harder cheeses consistently have the lowest carbohydrate counts, often registering as zero on nutrition labels due to regulatory rounding rules.
A Carb Ranking of Popular Cheese Varieties
Cheeses fall into two categories based on carbohydrate content: very low-carb aged varieties and fresh or processed options. Aged, hard cheeses have the lowest numbers due to extensive lactose conversion. For example, a one-ounce serving of aged cheddar typically contains less than 0.5 grams of carbohydrates, making it suitable for strict low-carb diets.
Other hard and semi-hard cheeses, such as Swiss, Gouda, and Parmesan, also contain less than one gram of carbohydrate per one-ounce serving. Parmesan is particularly low, generally ranging from 0.7 to 0.9 grams per ounce, and blue cheese varieties often contain around 0.7 grams.
In contrast, fresh and soft cheeses retain more moisture and residual lactose. Cottage cheese and ricotta cheese are examples, with carbohydrate content ranging from 1.3 grams up to 3.4 grams per one-ounce serving, depending on the brand. Cream cheese is slightly lower, usually containing about one gram per ounce. Processed cheese slices, often labeled as a “cheese product,” can also have elevated carbohydrate counts, sometimes reaching two to three grams per slice due to added thickeners and stabilizers.
Strategic Inclusion in Low-Carb Eating Plans
While cheese is generally low in carbohydrates, portion control is important due to its caloric density. Cheese is rich in fat and protein, and overconsumption can significantly increase daily calorie intake and potentially slow weight loss progress. A standard serving size is typically one ounce, roughly the size of two dice.
Another consideration is the potential for hidden carbohydrates in pre-shredded and low-fat varieties. Pre-shredded cheese often contains anti-caking agents like potato starch, cornstarch, or powdered cellulose to prevent sticking. These starches are pure carbohydrates and can add up if large quantities are consumed.
Low-fat cheese products may also contain added fillers, such as gums or starches, to improve texture after the fat has been removed. This can increase the total carbohydrate count compared to full-fat versions. To avoid these added starches, it is best to buy cheese in block form and shred it manually at home. Incorporating cheese into a low-carb diet is best done by pairing it with non-starchy vegetables or using it as a source of healthy fats and flavor in moderation.