Yes, I am amazed at some doctors (and others) repeating stuff about calories.
The only way we measure calories in food stuff is to burn it (like a bomb calorie meter), while digestion is an entirely different and extremely complex process.
The two do not have ANY link. One might as well measure calories by e=mc^2 and start asking people to eat accordingly !
The closest approximation to digestion we have been able to make takes up 1000 cubic feet and still does around 10% of digestion like process with boatload of chemicals and pumps. On top of that, it is just able to output a few basic compounds that our bodies use and is not actually able to use any energy from the process but consumes a lot of electricity and chemicals for every pass.
So till we actually understand even half of digestion process, evolved over a few billion years in different animal and then in humans, it is best to just go by whats been done for ages by our forefathers - eat in moderation, exercise a few hours, sleep when sleepy and wake up when you can't sleep anymore or its dangerous to do so.