How safe and effective is calorie restriction?

How safe and effective is calorie restriction?

It's very easy if you hear that kind of restriction is a good idea and might save your life to get it wrong. To essentially starve yourself of calories, but at the same time, starve yourself of micronutrient's that you need. And the most effective calorie restriction in experiments that have been done in the laboratory on rats and mice and such have be done my carefully enriching the food in various micronutrients. So, that even though the animal's are not getting so many calories, they're getting plenty of everything else. Now, of course, we can do this as humans as well, just by being very careful about the composition of our diet. And, certainly people who do calorie restriction, themselves, have a very rigid regimen of determining exactly what they're getting and what they're not getting, and making sure that they don't get short of any micronutrient's. If you do that, then I think the overwhelming evidence, is that, doing calorie restriction is indeed safe. The new doubt I have is whether it's truly effective.