I should add this here:
Manipulations to set back biological age and extend lifespan in animal models are well established, and translation to humans has begun. The length of human life makes it impractical to evaluate results by plotting mortality curves, so surrogate markers of age have been suggested and, at present, the best established surrogates are DNA methylation clocks. Herein we report on a randomized, controlled clinical trial designed to be a first step in evaluating the effect of a diet and lifestyle intervention on biological age. Compared to participants in the control group (n=20), participants in the treatment group tested an average 3.23 years younger at the end of the eight-week program according to the Horvath DNAmAge clock (p=0.018). Those in the treatment group (n=18) tested an average 1.96 years younger at the end of the program compared to the same individuals at the beginning with a strong trend towards significance (p=0.066 for within group change). This is the first such trial to demonstrate a potential reversal of biological age. In this study, the intervention was confined to diet and lifestyle changes previously identified as safe to use. The prescribed program included multiple components with documented mechanistic activity on epigenetic pathways, including moderate exercise, breathing exercises for stress, and a diet rich in methyl donor nutrients and polyphenols.
I do almost everything on the list in this study already. In addition, I have a low body temperature, which means I have a low metabolism. That's perfectly fine, if you can keep from overeating -- in fact, you can be very athletic, healthy, good-looking... and have a slow metabolism, if you watch your diet. I am very careful about my diet, and consequently am not overweight. And so, I get to reap the benefits of slowed aging -- processes that produce a high metabolic rate cause a more rapid breakdown in bodily structure, and consequently lead to accelerated aging; and, conversely.
In fact, many fat people are probably individuals with the right metabolic profile to slow aging, that were unsuccessful in also controlling food intake.
In fact,speaking of diets, I'm on a 72-hour fast. Not for any weight loss benefits; but because that is long enough to induce autophagy and clean out damaged proteins.
If I didn't have other things to worry about (that require a little extra energy from food), I'd do it even longer.