Greek yogurt is a type of yogurt that is made by straining extra liquid from regular yogurt. There is some lactose in Greek yogurt, but less than in regular yogurt or in most other dairy products. Many people who are mildly lactose intolerant are able to eat Greek yogurt.
Much of the lactose in dairy products is found in the whey, which is the sweet, liquid portion of the milk. The amount of lactose is lessened by straining out this liquid. By way of comparison, a standard 6-ounce (about 170 grams) container of American-style yogurt contains about 11 grams of lactose. A 6-ounce container of Greek yogurt contains only around 7 grams of lactose.
The exact amount of lactose in Greek yogurt will vary somewhat depending on how much it is strained. Some yogurt brands may advertise the amount of lactose found in their yogurt, but others may not. In general, the thicker the yogurt the less lactose it contains. Sometimes the amount of lactose in Greek yogurt can be estimated from the total amount of sugar listed in the nutrition facts. All the natural sugar in yogurt is lactose, so the total sugar minus sugar from fruit or other sweeteners will equal the amount of lactose.
Some of the lactose in Greek yogurt or other types of yogurt with live, active cultures will have been already digested by the bacterial cultures. Since Greek yogurt generally has a higher concentration of live cultures than most other yogurt, it is often easier for people with lactose intolerance to digest. People with severe lactose intolerance, however, may still not be able to eat Greek yogurt.
Lactose intolerance is a condition in which the body cannot digest lactose, or milk sugar. People with lactose intolerance lack sufficient quantities of the enzyme lactase, which breaks down lactose. Consuming dairy products with lactose may cause these people to experience abdominal pain, diarrhea or nausea.