It takes a lot of protein to forge the kind of muscles you want. That’s why you scarf down pounds of chicken breasts and lean beef, schools of fish, dozens of eggs and gallons of low-fat dairy products. It’s important to eat a variety of protein sources, as they all provide different benefits. Dairy, for example, contains both whey and casein proteins, which are superior because they’re rich in branched-chain amino acids and glutamine.

Yet dairy poses a problem for many tummies because it contains lactose. Lactose is composed of the simple sugars glucose and galactose, which are connected by what’s known as a beta-1,4-glycosidic bond. Many people have inadequate stores of the enzyme lactase in their digestive tracts, preventing them from being able to break the bond between glucose and galactose to digest them. This results in a condition known as lactose intolerance, the uncomfortable feeling many people get in their stomachs 30–120 minutes after consuming dairy. Symptoms may include nausea, cramps, bloating, gas and diarrhea.

The Numbers

Between 30 million and 50 million Americans are lactose intolerant, including up to 80% of African-Americans, more than 80% of American Indians and more than 90% of Asian-Americans. Some bodybuilders are so intolerant that they experience symptoms from even the small amount of lactose found in some protein powders, such as milk protein, whey protein and casein protein. Reduced digestion of lactose can also affect your entire meal, resulting in decreased digestion (and absorption) of protein, vitamins and total calories.

There’s Hope for You

You may think that if you’re lactose intolerant, you just have to sacrifice the benefits of dairy. Yet there’s an alternative: Popping a couple of lactase enzyme supplements right before consuming dairy could help ensure that all the nutrients wind up in your muscles, not the toilet. Lactase enzymes have been shown in several clinical trials to effectively increase lactose digestion; these studies indicate that even subjects who are considered highly lactose intolerant can consume dairy products if they take enzyme supplements.

When choosing a lactase enzyme supplement, look for a product standardized for Food Chemical Codex (FCC) lactase units. This signifies the product is produced according to FCC standards to break the bonds holding lactose together. Each person’s ability to digest lactose varies, so you have to experiment to find out how much supplemental lactase your body needs.

If you consider yourself to be moderately lactose intolerant, start by taking 2,500–5,000 FCC units of lactase when consuming dairy-based protein supplements or foods. Those who are more sensitive to dairy should start with 10,000–20,000 FCC units. If your lactase supplement is in capsule form, make sure you take it at least 15 minutes before consuming dairy so your stomach has time to break down the capsule. Lactase powders or chewable supplements can be ingested at the same time as dairy.