If you have a need to be seen maybe a yen or desired, better as a skinny boy squeezing into these items than a chub. Weird?, maybe but again to what harm. Only warning is pick and choose where you wear, enjoy but do not set yourself up for physical or verbal abuse. 1. The undershirt makes unsightly lumps and bumps in the World Depopulation Forum Shirt but I will buy this shirt and I will love this belly or sides less noticeable. Creating a more uniform and smooth appearance. 2. It acts as a buffer or sponge to prevent daily sweat form becoming visible in areas like under the arms or on the back where the clothes are generally pressed up against the skin. 3. Modesty. I have a hairy chest. It can be somewhat unsightly for some people to see body hair. The undershirt has a high enough neck line that it keeps my chest covered. The same concept applies for in the back when a button up shirt becomes untucked and the skin and upper butt become visible. Since the undershirt is cotton, it tends to stay tucked longer.