It's a bit of a generalization, but calories and texture are a fuction of malt content which in turn is a function of alcohol content.
Simply put, your higher malt content beers are high alcohol % and have a much more "filling" texture to them. The higher the ac% the higher the calories.
Beer is a function of grains, sugar(malts), hops and yeast.
The grains give it the color, flavor and some texture. The sugar gives it most of weight/body(and ac%), the hops help balance out the sweetness of the sugar and give aroma, and the yeast sort of ties the whole package together.
I'm only familiar with the ale style of brews. Lagers are a different beast. And in ales, wheats are some of the simplest brews to make. They simply take wheat grains, a modest amount of malt, and a modest helping of hops. This makes for a light beer in the simplest terms. It's low sugar, simple grains, and not overwhelming on the hops. Goes down easy and isn't "filling".
When you start getting into your high octane IPA's, Stouts, and various other ales you are dropping in literally gallons of malt extract that is a sludge in consistency to bring up the sugar/ac%. It's that malt heavy side of things that makes them sit heavy in the belly.
Think of drinking a non-sweetened tea vs. a sugar laden sweet tea.