Yep; I almost did not post this for fear of starting a fight. But, I thought this might be useful to the OP since calorie restriction (CR) does seem to have a positive impact on most markers. While I am not convinced that CR will add a significant number of years to the end of my life, I am convinced that it gives me the best chance of being healthy and active in those ending years. And, I thought it might be somewhat new and useful to the OP since this does not seem to get nearly as much media attention as some of the other dietary approaches even though it has a fairly large number of animal studies supporting its benefits.
This is definitely something that should be slowly phased in if it is tried at all. Quickly reducing caloric intake has definitely been shown to contribute to a laundry list of issues in adults.
My approach has been to track my calories in minute detail (the way some here track spending) and only reduce intake by 50 calories per week any time my weight stabilizes for about a month. I am still having my two (sometimes three) beers in the evening (for the B vitamins); but, I have all but cut out the cake, cookies, etc. For me, smaller portions were the key to most things; but, I have all but cut out some others like soda, french fries, etc.