Sorry my internet was fucking up.
I have read that in a number of places, do I have the time to go pull studies for you know sorry, but a man of his size eatting 700-1200 calories a day is surely unhealthy. go look up BMR his is around 2K. you can lose weight on a 1200 calorie a day diet it is true, but if you go under that you are putting your body into starvation mode. And I don't give a shit what you can run rats on because they have very different metabolic needs then humans.
Honestly if he were really eatting 1200 calories a day and cycling 100 miles a week I highly doubt he would be the size that he is. sorry but its just not realistic. My mother in her 50's is 5'4'' 135 and looses weight if she goes under 2000K yes she was eating 1200 to 1500 to get to that weight but to maintain she had to up to over 2000. she has done every crash diet in the world and yoyo'd in the range of 65 pounds before finally starting to count calories, so dont give me this messed up metabolism stuff unless someone has a thyroid problem.