Two things: first, a nutritionist put me on a 1800 cal and I was gaining, she reduced it through 1500, 1200 and finally at 1000 I began to loose. I did fine on it for nine months loosing about 65 lbs. She increased me to 1200 and then to 1500, her goal being 2000 per day. At 1500 I began to gain weight again. I was moderately active, jogging 3 to 5 miles a day four or 5 times a week. As we get older we require less calories.
The t theoapy is good, however it does have a draw back. As we age we are more pron to cancer. Many types of cancer grow best in a high testastrone environment. There for for older males t becomes risky.
All of that said, we each make choices every day. Hopefully we make informed choces.