That's interesting. I can see the sense in that, but it runs counter to what I've been led to believe is the case for cyclists. There's even a calculation that converts your average power output into calories burnt.
To work out energy expenditure in joules, you multiply average power (/1000) by time in seconds. Thus, the work done in 1-hr at 190 W avg is 684 kj (0.19 x 3600). To convert this to kcal you divide by 4.18, i.e., 164 kcal.
However, the human body when cycling is only around 25% efficient (normal range ~ 20 - 26%), thus, this needs to be calculated, to work out the human energy consumption, i.e., 164 / 0.25 = 656 kcal.
190 watts btw is reasonably low, and would give you a speed of around 30km/hr on a flat road.
So in other words, the faster you go, and the more watts you put out to achieve that, the more calories you'll burn, even if you are more efficient at burning them than a layman.