About 15 years ago, an Italian woman died at age 126. She rode a bicycle until she was about 115 (went blind). When asked about her secret to longevity, she said she drank about a cup of olive oil per day, and drank lots of red wine. I forget if she ate any food or not.
As you age, your body needs fewer calories. The more you eat, the harder your body has to work to digest what you ate. Free radicals are spawned as a result of metabolic processes. The less you eat, the less your body has to work. In a way, retirement should be not just retirement from work but from eating as well, if you can hack that.
My grandfather still has a glass of wine a day, swims laps in his community pool, but he eats very little. Coffee and toast in the morning, a light salad for lunch, and he often doesn’t even eat dinner. He’s 82 but appears no older than 65. I pray I live to the same age.