Now this is an interesting question. If I can explain.
Your desire to live longer needs to specify longer than what. Longer than everyone else in the world. Longer than you personaly would normally without some intervention. What if you personaly are destined to be hit by a bus and we tell you to look out for busses. Then there is one thing you need to keep in mind. The average life expectancy of the individual in a specific society. Life expectancy in one country or even in a certain part of that society is not the same as in another due to the environmental factors which includes social unrest or polution plus even food availability and your standing in that society. Even the type of job you do can shorten your life.
Life expectancy on average has increased over the last 100 years for a given population.
Then the health issue. Did you know that the medical research is not specificaly working on increasing the number of years anyone lives BUT it is working on keeping you healthy and active for more years of your natural life where you do not spend the last 10 years before death in a bed and not able to walk or even think. Keeping you in a physical and mental state that lets you do what you have always done.
And diet is a very small part, but important thing in the game of living longer and healthy. And there is a question you need to consider. What do you do in your day. A highly physically active person needs to eat totaly different things to someone working in an office all day.
The best suggestion anyone can give you about diet is … energy in should equal energy out and quality not quantity.