Calorific restriction... regularly eating less in the day, energywise, than your body needs over a long period of time may be of significance in extending your lifespan(vegan or not may not be that important). However most Westerners would be grumpy bollixs, if they subjected themselves to daily semi - starvation.
Avoiding long term over eating is probably the issue and avoiding obesity helps cut diabetes and heart disease rates and lower the occurrence of certain cancers.
Avoiding overly processed foods is also the way to go. A lifetime of sausages and rashers may do you more harm than moderate consumption of unprocessed lean meat.
<><><><><><><><><><><><><><><><><><><><><>
Shalom/salaam.
10,000 years of Middle Eastern civilisation and the place is not at peace but rather in pieces.