When someone reports he lost 15 pounds in so many weeks while riding a certain number of miles, you ought ask yourself, "What is this guy's age?" I could lose weight in a predictable way until I hit 38 years of age. Then it became more difficult. I am now 62 and losing weight does not seem to be so simple as calories in vs. calories expended. My body has turned into an unpredictable trickster.
Because of time and stamina, I can manage about 100 miles a week, at most. Once I could lose two pounds a week like clockwork at that amount. Now the scale just sits there and I am eating more wisely than ever. I read things that say weight loss happens when you hit 150 miles per week.
I lost 15 pounds of weight my first year back to cycling. It was in fits and starts. The scale would drop ever so little. Then it would bounce back up, sometimes seemingly for no reason. But, miraculously, little by little, the weight did come down to about 210 pounds. Six or more months later I am 203 pounds and have been for several weeks. I am also working at losing the same five pounds for the fourth time in my life. I would like to get back down to 180 pounds, but I am giving myself about a decade to do that.
I downloaded a bicycling podcast from KBOO radio in Portland, OR about two guys who lost a lot of weight on bicycles. When they got to about 215 pounds they both noticed their rates of weight loss slowed dramatically, even though their eating habits were still good.
When some guy says it is simply calories in vs. calories expended I begin to wish he could spend a year or two in my skin. It is not always that simple.