Assuming adequate nutritional intake, what is the "optimal" level of caloric restriction? At what percentage, if any, assuming adequate nutritional intake, are there no more benefits?

[Afraid to Use my Real Name]

Say someone with my height, weight, age and activity level needs to consume 2,000 calories per day. As an aside, the actual tool I use as a reference point when determining what percentage caloric restriction I'm doing is the one at this link: https://www.nal.usda.gov/fnic/dri-calculator/.

If reducing caloric intake by 50%, and consuming 1,000 calories a day doubled my lifespan, would reducing my daily caloric intake by 75%, and consuming 500 calories per day, quadruple my lifespan?

Basically, I think what I'm trying to ask is if the increase in lifespan from caloric restriction is inversely proportional to the percentage caloric restriction an individual is doing.

And, is there any minimum caloric intake individuals practicing caloric restriction for longevity should have, just for the sake of having calories? What I mean is, say there was a way for an individual to get all the nutrients they need, somehow, in only 500 calories a day. Would increasing calories at that point help with longevity in any way?

Edited April 10 by Afraid to Use my Real Name

[Thomas G]

Unfortunately nobody knows. At this point the research into whether or not calorie restriction will have any significant life extension for humans is inconclusive at best, but I think it is safe to say there is less optimism than there used to be.

There is no real consensus as to what "counts" as being calorie restricted in the first place, let alone what the optimal level of restriction might be.

[mccoy]

On 4/10/2020 at 8:24 PM, Afraid to Use my Real Name said:

If reducing caloric intake by 50%, and consuming 1,000 calories a day doubled my lifespan, would reducing my daily caloric intake by 75%, and consuming 500 calories per day, quadruple my lifespan?

It doesn't work that way. Like Thomas wrote, it has not been rigorously proven that CR will benefit longevity, even less a dose-response relationship has been proposed.

But it has been proven that some health and longevity benchmarks do improve with CR. In my anecdotal opinion, a little CR with optimal nutrition and healthy, plant-based regime, will usually improve health and longevity, but everyone needs to tune oneself adequately as to the severity of CR. Also, CR will undoubtedly benefit people with a tendency to overweight/obesity.