Big deal, you say.
Well, normally I'd say that too.
Except I noticed one significant difference between those running and walking at 0630 and those doing the same at 0730.
About 10 kilos.
The only people up and about at 0630 were the very fit, skinny looking people. Those plodding around at 0730 were also pretty fit looking (compared to the average non-exercising tub of lard), but it was like the difference between your average gym junkie body builder and Arnie in his prime.
The only thing I can discern from that observation is that it's possible that the early risers and skinnier because they exercise for longer. If both groups need to be at work at say 0830, someone getting up half an hour earlier will crank out 2.5 extra hours of exercise and sweat per week. Over the course of a few months, that adds up. Or subtracts. Take your pick.
So if you want to lose weight, set the alarm for really early and walk much further than you normally would. Pretty simple concept.
Just hard to put into practice when the alarm goes off at Oh-dark-hundred.