As a teen, losing weight and getting fit was ALL about counting calories. We were told women should have this many and men should have this many, end of story. In reality, having a healthy diet is much more complex than sticking to a certain number of calories.
In theory, if you eat less calories than you burn in a day, you will lose weight. If you eat more calories than you burn in a day, you will gain weight. That’s the basic rule of calories, but is it that simple when calories don’t necessarily tell you the real nutritional value of something (case en point, avocados)?