Just to clarify, having heavy meats like a tenderloin steak or a chicken burger for breakfast is probably not the best way to start off one's day. But having nutritious foods like eggs, mils, oats and fruits give a very healthy start to the day.
These places also offer special breakfast deals, to appeal to the customers and encourage them to have a good and complete breakfast. And not to forget brunch, many up-scale and budget restaurants all, are offering brunch these days, owing to its high demand in the major cities.
Since breakfast is so important one should keep in mind that it must be heavy, not too heavy, but essentially breakfast is the heaviest meal of the day. One should eat a full set of breakfast and not skimp on anything. Items like eggs, pancakes, waffles, cereal, for the more Indian options there are pohaa, idli, jam and butter toast, oatmeal, moong dal ka cheela, misal pav and upma.
There are literally hundreds of option for a hearty breakfast, so don't skip it and instead enjoy it.