Diet and exercise is one thing but your genes and surroundings are completely different and hard to control. Most of these youngins parents grew up on fast food and life is much faster than it was back in the day. Watching TV, playing on your phone/video game and going on the internet isn't great for your health. Most of these bytches probably grew up in a small village where they worked on the field and got plenty of sun shine and went to church every fuking night. They wasn't out there twerkin, instragramming, getting tossed up eating Mcdonalds at 1AM the night before they had a exam or work in the morning.
diet isnt the only determining factor when it comes to living that long.
those people you talkin about that worked in the fields also smoked 3 packs of unfiltered cigarettes everyday...and drank water from a lake that all the animals take shyts in....and didnt get their kids vaccinated because of insufficient means and/or ignorance.
if we're living overall unhealthier lives, then the average lifespan would be getting shorter. but its getting longer, at a fast rate too. once this stem cell research REALLY gets crackin we're gonna see some amazing medical advancements. poor diet and sedentary lifestyle may lead to heart problems...but 20 years from now we might be able to grow new hearts in a lab...so it might not be an issue at all.
i dunno we'll just have to wait n see. imma live to be about 120 tho thats for sure. your boy gonna be gettin his dikk sucked on the moon n shyt.