Lactose intolerance, sometimes called lactase deficiency, is an inability to fully digest the milk sugar (lactose) in dairy products. Symptoms of lactose intolerance–diarrhea, nausea, abdominal cramps, bloating and gas–can be uncomfortable and usually begin 30 minutes to 2 hours after consuming lactose-containing foods or beverages. Lactose intolerance is not unusual after weight loss surgery, beginning with the full liquid phase when milk can be relied upon for a protein source.
Lactose intolerance is most commonly diagnosed by elimination of all dairy products from the diet for a period of two weeks. If symptoms disappear, lactose intolerance is suspected. To confirm, your doctor may follow up with the following tests:
A hydrogen breath test measures the level of hydrogen in your breath 3-5 hours after drinking lactose-containing drinks. Normally, there is very little hydrogen in the breath, but when lactose isn’t broken down properly, hydrogen begins to build up in your body and is expelled through your breath.
A lactose tolerance test measures the rise in blood sugar level after a fast followed by drinking a lactose-laden drink. Since lactose is a sugar, when it breaks down, it releases sugar into the bloodstream. If blood sugar levels don’t increase as expected, then your body is not breaking down lactose properly.
If lactose tolerance is confirmed, you may be able to prevent symptoms by:
- Keeping a food log to learn how much dairy you can tolerate—most people are able to relieve symptoms by decreasing rather than eliminating lactose from their diet.
- Consume dairy products with other foods rather than alone, making it easier for your body to digest the lactose.
- Use ready-to-drink lactose-free protein supplements or lactose-free protein powders.
- Many people with lactose intolerance can still eat cheese, yogurt, and cottage cheese—at least in limited amounts.
- Use lactose-free or reduced-lactose milk and dairy products. These have most of the lactose removed or lactase (the enzyme needed to break down lactose) added.
- Pretreat milk yourself with over-the-counter lactose formulas, such as Dairy Ease and Lactaid. Add the liquid form to milk and refrigerate for 24 hours. The milk tastes slightly sweeter and has the same shelf life.
- Use nondairy options, such as almond, rice, or soy milks. Be sure to check the sugar content—look for no-added-sugar options.
- Take a lactase enzyme replacement. These are available over-the-counter. Dairy-ease in pills or liquids.
- Try Digestive Advantage, Lactose Intolerance Defense, a lactase and probiotic supplement.