How to tell the calories in something

So, I had an epiphany (again). Another way to determine how bad something is for is it's weight and overall density. How, you might wonder, does this matter? Well, if something is heavier, given it's volume, then it weighs more and if you eat that, then you too will weigh more. Simple, right? So, to determine how bad something is, one method is to see if it floats. For example, I had a root beer float the other day. The ice cream floated (hence the name!), which means that it's good for me! I love science!