Thicker and Wider are two different things. Thicker implies density, wider implies a structure change. How do you know deadlifts are what made your waist "thicker"? How are you able to pinpoint deadlifts as the one sole culprit for a "thicker" waist. You sure it wasn't all of the gear you've done or the food you've eaten? I agree 100% deadlifts make your back thicker but I dont agree they "widen" your waste.