Diet and testosterone levels

can short or long terms dieting cause a significant suppression of testosterone? Currently 21 years old 6 foot 2 male and have been long term dieting for my job (actor/ model). I suffer from low test and thyroid. Curious on your thoughts on this? Also I'm on exogenous TRT and thyroid replacement, but doctor wants me off testosterone once I gain more weight and check bloods. I asked if a pct would be needed to increase my lh and natural test and he said no. Your thoughts? Thanks!