Problem is we all die of something. Is adding those years risking a worse death? For example, perhaps you have a heart attack and die or you follow this and get 4 years but along comes cancer or something worse.
Intermittent fasting supposedly reduces the chances of cancer
As someone who has followed a very intense, primarily no-meat, calorie-restricted diet since 2016, I can tell you the question is NOT adding more years, but adding more HEALTHY years.
It works for me! At almost 80 and living on a 1000-calorie-a-day diet for 8 years, I'm still very active, walk three to five miles a day, and continue to work full-time.
I started this for medical reasons. It worked better than expected.
While I fully understand it is not for everyone, it has changed my life. I no longer "live to eat" but "eat to live."
You should try it.