In the United States, almost all food must be packaged with a Nutrition Facts label that lists the nutritional value of the food. These labels contain important information about the food, including the number of calories in a serving, the serving size, and the amount of macronutrients and micronutrients.
Nutrition Facts labels are nearly ubiquitous, though there are many foods that do not require them. These include alcohol, food sold for immediate consumption (at restaurants, street vendors or elsewhere), fresh produce, spices and foods that contain very few nutrients, such as coffee or tea. Nutritional information exists for these foods, but does not need to be directly on the packaging. Instead, many restaurants, especially larger chains, provide this information online. Additionally, FastFoodNutrition.org lists many popular fast food restaurants and the nutritional information for all current and discontinued products.
Specialty websites, such as NutritionData.self.com, contain a much more exhaustive database of all foods, including different preparations of them (for example, an apple with skin has different information than a peeled apple). For meals at small restaurants or home-cooked meals, accurate nutrition data may not exist. In these cases, obtaining accurate data requires adding up the ingredients used in the recipe. This provides a much more accurate set of data than a website provides, particularly for recipes that can vary by family, such as chicken noodle soup.