Take two numbers, height and weight, and come up with another number, Body Mass Index (BMI), and as an indicator of good health you have next to nothing. The BMI fails to take into account physical features - as an example those with broad shoulders will have a higher BMI compared to those with narrow shoulders. There is no differentiation between fat, muscle, and bone, and it does not account for gender.
The BMI often changes as we age. For some it is lower, but that does not necessarily mean better health. Thirty years ago I was in peak physical condition and had more muscle mass than I do today; I regularly played rugby, two 40 minutes halves of pretty much non-stop strenuous exertion with no substitutions. According to this BMI chart I would have been bordering on obesity and classified as unhealthy.