In the United States, a product can only be labeled as “yogurt” if it contains live Lactobacillus bulgaricus and Streptococcus thermophilus bacteria. Some yogurt varieties have a “Live & Active Cultures” seal on them, which was created by the National Yogurt Association and means that a product contains at least 100 million organisms per gram at the time of manufacture. But even if it has no seal, it’s still yogurt as long as it contains those two types of bacteria. Another thing to look out for on the product label is sugar content. Comparing ingredients lists and Nutrition Facts panels can give you an idea of whether a yogurt is lightly sweetened, or more like sugar with added yogurt.