I have thought about this too and while I think it is a good starting point, there are many variables you may not have thought of, such as is it about heart rat

I have thought about this too and while I think it is a good starting point, there are many variables you may not have thought of, such as is it about heart rate on average or perhaps more about actual number of heart beats in a lifespan (eg, short high-intensity workouts vs distance running? Drugs that increase heart rate being used daily, etc) I honestly think it might not be about caloric intake itself, but the content of those calories. Papers like this: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3718635/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3718635/ Make me wonder what the effect of certain foods might be on telomere and mitochondria. In the same way it has been shown that charred or overcooked meats (red meats in particular) can have certain adverse long term effects, it makes me wonder if certain chemicals or cooking methods contribute to reduction of effenciency in cells mitocondria or can cause dna damage that results in shorter life spans. In this case, the increase in caloric consumption might just be that with more calories in, the more likely some of those calories are to be ones that might damage some tissue functionality somehow, and it's the actual calories to life expectancy is more of a correlation and less of a causation. Here is a paper that showed "For every 1 serving/d greater intake of processed meat, the T/S ratio was 0.07 smaller". http://ajcn.nutrition.org/content/88/5/1405.full http://ajcn.nutrition.org/content/88/5/1405.full On your note though, I would say everything we have talked about indicates that one particular combo would seem to be an ideal starting point for reaching an effecient balance: high intensity excercise to increase metabolic effeciency paired with meditation excercise to reduce standing heart rate/stress hormones.