news story today - 500 calories

[OakLeaf]

But I wonder what the activity level is/was for any of these groups - the study participants, the mice, the ascetics.

The picture I have in my head of the ascetics is people spending the day in stationary prayer and meditation, eating so little because it is what they get from begging, but also having an extremely minimal caloric burn, sweat rate and micronutrient requirement (unlike other types of monks who subsistence farm as a form of strenuous active prayer).

The abstract of the paper isn't online yet, but Medscape has a summary. It doesn't mention activity level at all. And it's too early for me to bother looking up the mouse study.

It's notable too that the study was done by radiologists and primarily focused on pericardial fat and heart function. Heart function regressed along with the weight regain in the follow-up period, but pericardial fat returned at a significantly lower rate. I'd like to see endocrinologists' and exercise physiologists' take on this. I don't doubt that getting off insulin is major. But the summary says over and over again how highly motivated the study participants were and how dangerous the regimen was, how it should be undertaken only under strict medical supervision.

The fact that all the hoopla in the press is about the weight loss and glucose tolerance, when what they were actually studying was heart function - well....

I just can't imagine that a diet like this would provide enough protein, electrolytes, vitamins or minerals to sustain activity. Bare calories for ADLs and gentle exertion can come from body fat, but what about asking these people to raise their heart rates? And were they getting most of their nutrition from pills?

I know what I need when I'm in even a minimal training cycle, and I know that even when I'm in the peak of marathon training, my daily activity is LESS strenuous and less sustained than humans evolved for. I think it's basically only the Iron men and women who exert themselves as much as every one of our ancestors did every day. I just don't see it.