Fitness has ties to appearance no doubt but is by no means a substitute. BMI is often times as much a reflection of genetics as it is fitness and frankly is based off of assumptions centered in appearances.
I’m all about fitness and living a healthy lifestyle. Lifestyle choices will add years and in some cases decades of high quality life years. There is no substitute for healthy lifestyle choices that lead to cardiovascular fitness.
But even the strictest lifestyle choices with the paid programs advertised on TV will not make me look like Matthew McConaughey in his prime. I’ll look better and feel better and be stronger and tighter but I won’t have that physique. Ever.