LOL! If you exercise and eat healthily, you will age well. Cor! We talk like some one foot in the grave, geriatrics!
You know what I think is one of the most important things about eating healthy is? It's not eating much at all, i.e. calorie restriction.
I learned it on my thru-hike of the Appalachian Trail. Long story short, while hiking the trail you are forced to basically run on caloric "fumes" day-after-day, until you get to the next town and resupply and eat all you can in restaurant(s); this is all because you can only carry so much, thus you must ration your food, but at the same time you're walking over mountains all day with a weight on your back -- fun stuff
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In the beginning you're irritable and are usually in a state of very low energy; however, after a while your body becomes super efficient. I was totally surprised at how much I could do on so little food.
After my hike, I started looking into this issue and, again, long story short, I am now convinced more than ever that we Westerners eat way too much food. Everyone hears that about eating way too much food, but it's one thing to hear about it and another to know from experience. I now am very conscious of not eating too much and at times I do very long rides and such on an empty stomach.
However, with that said, I see weightlifting and other exercises very important for us ageing folks, simply because if we don't we will lose muscle mass, no matter how good our diet is we will lose it, if we don't use it. You can eat all the quality protein in the world, but if you're not exercising your muscles, they will get weaker and weaker, until you have a fall or some other negative effect of an ageing body.
BTW, here's a very good article on Torbjørn Sindballe, a Danish professional triathlete who would train on an empty stomach
https://www.triathlete.com/2014/06/nutrition/inside-triathlon-magazine-fat-burning-machine_31034