How do I Know if My Metabolism is Slow?

Most people understand that almost every weight loss diet program, whether it restricts carbs, fat or counts points, has the end goal of consuming less calories. After all, eating fewer calories in the end is what will cause you to lose weight. With this in mind, many people wonder how to figure out how many calories they need to eat to maintain weight, and then how many they should eat to lose weight. What if your metabolism is slow and how do you know if it is?