Families have three key weapons in combating America’s childhood obesity epidemic: keeping them active, reducing their soda and junk food intake and teaching youngsters how to read food labels.

According to the National Center for Health Statistics, obesity more than doubled in children ages 6 to 11 and tripled in adolescents ages 12 to 19 between 1980 and 2010. Nearly one in five youths in both age groups, plus one in eight preschoolers, are now considered obese and at increased risk for consequent health problems. By 2013, the Centers for Disease Control finally showed signs of hope, with some states reporting small reversals in the trend.

Positive developments might continue if parents and teachers gently coach kids to better evaluate what’s going into their mouths and bodies by understanding food labels. Despite the intimidation factor (even for adults), “Once children know how to read, they are ready to start learning how to read food labels,” advises Jolly Backer, CEO of Fresh Healthy Vending, a forward-thinking company actively increasing the presence of healthy-food vending machines in schools nationwide. He says, “The more kids know about what they’re eating, the more empowered they’ll be about making healthier food choices.”

Here are five basic tips to increase knowing what food labels really say that will benefit a youngster’s health for a lifetime.

Visualize serving sizes. Assemble two or three packaged food items—preferably those that the child regularly eats, like cereal, oatmeal and applesauce—plus a measuring cup. Point out the serving-size number on the package label, and let the child measure out a single serving. This visually reinforces serving sizes, the first number anyone needs to consider on a food label. Try it with a single soda or juice bottle, too, which often says, “two servings.”

Important note: Most nutrition label serving sizes are based on a 2,000-calorie adult diet. For kids ages 4 to 8, portion sizes are about two-thirds of an adult portion; for preteens, portions run 80 to 90 percent of the adult amount, says Registered Dietitian Tara Dellolacono-Thies, food coach for CLIF Kid nutrient-rich organic energy snacks.

Evaluate numbers. Next, discuss the numbers noted for calories, fat, sugar, fiber and cholesterol. When evaluating a packaged food for an elementary school child, Dellolacono-Thies suggests aiming for 175 calories or less per serving; one gram or less saturated fat; no trans fats; no more than 13 grams of added sugars; no more than 210 milligrams sodium content; and at least two grams of fiber. She notes that cholesterol alone is less of a health risk factor for kids than saturated fats and sugars unless a child is on a specialized diet. Added bonuses: Look for high-percent daily values (shown as DV percentage) for nutrients such as calcium, iron, zinc and vitamin D, which experts generally agree most kids’ diets lack in sufficient quantities.

Compare and contrast. Armed with these basic guidelines, compare, for example, the grams of sugar in a can of soda with a serving of cooked rolled oats, or the amount of calcium in a carton of milk versus a juice box. One-to-one evaluations will begin to give a child a sense of what numbers constitute “high” or “low” amounts.

Check the fine print. “Artificial colors and flavors, artificial sweeteners, high-fructose corn syrup or partially hydrogenated anything signal that the food is likely of lower nutritional quality,” counsels Dellolacono-Thies.

Make a game of sounding out items in the ingredient list. “It’s a classic teaching moment: Unpronounceable ingredients often mean it’s a lab-created, fake, food-like item,” she says. Next, ask the youngster to read the label on an apple. Surprise! No food label means it’s a whole, real food—the best, most nutritious kind.

Translate knowledge into choices. Once a child has gotten the hang of it, let him or her compare different food labels and choose which one is the healthier option. Plan a little extra time to also do it during grocery shopping. With time and practice, an educated youngster will begin to incorporate the power of reading food labels before choosing foods.

“Even when children walk up to a vending machine, where they can’t read labels, you want them to know which is the healthier option,” says Backer. “With label-reading practice, they’ll become savvy shoppers who’ll readily recognize healthy food options when they see them.”

Elisa Bosley is senior food editor at Delicious Living magazine.