I agree with this wholeheartedly. Just think about it. Your heart is a muscle that performs work. Work is defined by mass X distance. If you have greater mass, it's more work to move the same distance as the next guy. So you walk around with 50 pounds of muscle on your frame every day for 50 years, your heart is performing significantly more work.
My doc has told me that optimally I should lose 40 pounds, and it has nothing to do with whether my bodyfat is 10% or 20%. All things being equal, carrying less mass is less stress on the heart over time.
U guys are correct to an extint...However, look at the African elephant, they ALL have an average lifespan of 70+ years...I don't have to cite their weight...There are other species that are huge with similar lifespans or in some cases longer...No exceptions, the entire species lives to these average ages...So then, sometimes physics can be off...It has in the past...If the heart (as one of u stated, is a muscle) is exercised along with the accrued mass, which is generally muscle, then in my opinion, it will be able to carry the load...If what u guys are saying is 100%, then ALL PEOPLE who weigh light would have longer lifespans than the well known average of 70-80 years...Correct me if i'm wrong, but isn't that span pertinent to ALL PEOPLE, no matter their weight?...And yes there are exceptions to every rule of course, however, I'm seeing just as many big, small, and medium built people dying at the same average lifespan...Also consider the mouse as just one of many examples of a creature being small, yet having a considerable short lifespan of 4 years...I could go on with more examples of this...There are big, medium and small creatures that ALL have different lifespans even tho their body weights are similar...
Again, I'm seeing the main factor(s) being genetics and lifestyle...If u exercise (work),then relatively speaking, u will be fine...Now, if u are out of shape (not meaning what u weigh) but your internal conditioning, then yeah, I agree the more weight u carry, the higher the odds of u dying sooner do to the extra weight...