Even though the thickness of three inches is the most widely chosen size for a good mattress topper, you cannot go along well with it if you weight over 250 pounds. In this case your body needs a fuller support. A 4 inch foam mattress topper is sure to be an excellent choice for people with full weights. Moreover, this thickness of a topper makes it possible to use it when camping. You will be amazed how comfortable a thick mattress topper may feel when placed on the ground in the open nature.