Emily Heikes dropped dairy foods from her diet about a year ago.

"I ordered milk for breakfast in a restaurant and I got really sick. Not long after that, I bought some milk in a store and it made me sick again. I thought, 'Maybe it's not the best thing for me,'" said Heikes, 22. So she went dairy-free.

The Springfield woman is one of many people who have deleted milk, cheese, sour cream, butter and other dairy products from their diets. Some suffer from lactose intolerance, some have milk allergies, some have chosen not to eat animal products on principle and others say their health is better without them.

"I feel so much better when I don't eat dairy, I think it's better for the environment and I'm concerned about animal welfare," said Heikes. In fact, she has since given up all animal products and has gone vegan.

Causing trouble: Milk and dairy products usually are derived from cow's milk, which is perfectly formulated for calves. Human babies would get sick drinking cow's milk, so infant formulas based on cow's milk are altered so that babies can safely digest them.

Cow's milk contains many proteins, such as casein and whey. For people with milk allergies, proteins often are the trigger. Milk also contains sugar, or lactose, which causes problems for people who are lactose intolerant -- they have trouble digesting it.

Milk is considered a good source of nutrition, especially for children. It has vitamins, calcium and proteins and is further fortified with vitamins A and D. But it is possible to have a healthful diet without it.

"I think the transition is kind of hard. But as long as you put a little effort into it, you can do it," said Heikes.

Alisa Fleming is the senior editor of Allergic Living Magazine, editor of the website GoDairyFree.org and author of "Go Dairy Free: The Guide and Cookbook."

"People tell me that cheese is the thing they miss most. But the cravings do go away," said Fleming, who has a milk intolerance. "For those really addicted to cheese, most people find the craving goes away in six months to a year. If it doesn't, they're probably cheating."

Dana Bueno of Springfield said "no" to dairy more than five years ago in an effort to help with sinus problems. Giving up cheese was a hurdle for her but she found a substitute she likes: Daiya brand, which she buys at Food Fantasies in Springfield. She shares her favorite dairy-free recipes on her website, BuenoVida.com.

Other tips for the dairy-free eater:

Get calcium: Milk isn't the only food with calcium. It's abundant in almonds, blackstrap molasses, broccoli, enriched soy milk and rice milk, figs, leafy green vegetables (spinach, kale), salmon with bones, sesame seeds, soybeans and tofu, among others.

Find milk alternatives: Try soy milk, rice milk or almond milk. Both Heikes and Bueno drink almond milk.

Seek help: If you're new to dairy-free eating, check out websites such as GoDairyFree.org, notmilk.com, vegan.com/dairy-free and dairyfreecooking.about.com for more information and product recommendations.

Restaurant dining: Eating in restaurants can be tricky for anyone with dietary restrictions. It's the same for diners avoiding milk products.

When Fleming dines out, she questions the servers about the ingredients in the dishes, and asks if they can be made dairy-free. She offers this advice:

Go ethnic: Thai, Chinese, Vietnamese and Japanese cuisines are nearly dairy-free. African, Italian, Indian and Greek have plenty of no-dairy options.

Unload the potato: Skip the sour cream, butter and cheese that come on a loaded tater or whipped into mashed potatoes. Dress a potato with salsa or a nondairy salad dressing.

No cream in the coffee: Ask for soy milk to put in your coffee or tea. Many restaurants have it. Or bring along a packet of soy- or rice-based creamer.

Dress salads lightly: French or honey-mustard dressings, vinaigrette or oil and vinegar make good dairy-free salad toppers.

Double check on cheese. Chefs love to sprinkle parmesan on everything. Even if you've ordered "no cheese," the request may not have been fully conveyed to the kitchen. Fleming has learned to say, "and there won't be any cheese on that?" for just about everything she orders.

She also suggests looking at the restaurant menu online before you leave, or call ahead and ask about dairy-free options.

"When you sit down to dinner," she said, "you'll be able to enjoy your food."

Check the label: The Food Allergen Labeling and Consumer Protection Act requires that foods with milk ingredients use the term "milk" on the label, either in the ingredient list or in a separate "contains milk" statement. But the following words may also be a tip-off that the product contains milk ingredients: artificial butter flavor, butter fat, butter, butter oil, casein/caseinates, cream, curd, custard, ghee, lactalbumin, lactoglobulin, lactoferrin, lactulose, nougat, pudding, rennet, Recaldent, whey, yogurt.