the problem with calorie restriction

The desire to isolate calorie restriction (CR) and quantify its benefits renders it meaningless. What rational person would adopt a lifestyle knowing in advance they will be:

1. hungry most of the time
2. too weak to exercise

The CR proponents correctly note the 24/7 availability of unlimited calories is unnatural but go on to propose the equally unnatural practice of counting (and consciously limiting) calories every day of your life.

Traditional long-lived cultures are active into their 100s and there is no indication their diets provided insufficient fuel to maintain a strenuous lifestyle. The mimicry of longevity benefits through rat starvation is an academic exercise with little benefit for humans.