Secret of high expectancy of life/longevity depends on the awareness about diseases, readily and high quality of health services available not the type of food.
Fish is the best food.
Cooked meat is better than raw in tropics. Raw is fine in polar, tundra and subarctic.
Food is more healthier in developed nations than developing nations, veg or non veg.
Adulteration/contamination of Vegetarian food is easier than non-veg.
Eggs and meat have become more healthier than they were in last decade and before (developed nations).
Vegetarian food (grains, milk & milk products, vegetables, nuts etc) without pesticides, organic or GM if can be assured/found and eaten is more healthier than non-vegetarian food any given day. B-12 has to be supplemented; nothing else, if someone says you will still lack heaps of nutrients then he is bluffing or a meat fanboy.
Salt and sugar pose grievous threat to life, salt more than sugar after 30s. Fats can be digested with regular activity, same can be said about sugar but not salt.
If you give your kids milk with sugar you are doing wrong.
Try cooking food without salt or sugar, food itself has enough for minimum daily intake. Drink sips of Gatorade (neutralize with equal water above 30s or ORS type drinks if crave for sugar and salt is not going away, wean it off gradually.
Yearly S.electrolytes, cholesterol, PSA (for men), CBC, proctoscopy exam after 35-40.