Well, I don't agree with it that these heavy foods are fine for our health. Burger and pizza contains heavy calories and not suitable for fitness seekers. The people who want to be fit but strong should eat high protein foods like egg, fresh vegetables, oyster mushroom etc. Protein provide strength but don't make us fat.The article kid posted was on bulking up. To do that you've got to increase you caloric intake. Burgers and pizza are effective foods for doing that.
Bulking isn't a long term life style. It is more of a short term approach go adding body weight. It is an effective method even for "fitness seekers" as a means of increasing muscle mass.
Lyle McDonald (bodybuilding nutrition guru) has even stated that "eating clean" may not be the most effective ticket to gaining mass.
That in part has to do with the fact that you need to increase calories to increase muscle mass.
Also, high glycemic index foods stimulate insulin, a very anabolic hormone.
Unfortunately, insulin is a "fat maker". Thus, learning how and when to turn it on and off are important. It part science and part art.
By the way, exactly what are "heavy calories"?
Ingesting too many calories increases fat along with increasing muscle mass.
That means if you consume too many calories from protein, even protein will increase you body fat.