Very interesting! I (female; 57 y.o.) have been doing an intermittent fast (2 days/week: typically Tue/Thu) for >2.5 years now. I picked those days as they don't interfere with social events, weekends, long weekends. I initially did 500 calories on those days, but for more than a year now I simply don't eat at all on those days (but I drink coffee, tea). I find that much easier, as the hunger pangs are largely absent. Benefits from this fasting include an epigenetic reprogramming (perhaps?) of some stem cells, as from the outset I've seen a few of the very few gray hairs that I have revert back to brown (white further out; brown more recently to root). That could be triggered (or entirely due to) e.g. by autophagy of the old, weakened cells and their replacement by rejuvenated cells. Interesting, nonetheless. Body weight is stabilized around the new metabolic set point (I record this daily in a tab-delimited file, that I can easily plot with a simple linux command (alias gp='echo "gnuplot -p /mnt/Vancouver/Programming/scripts/gnuplot/plot.gp')! On non-diet days I eat whatever I want (I ashould add, pretty sensible: mostly home-made food, meals), ad libitum. ;-)