Weight loss/blood work update

I just wanted to update on my current situation. I have had great difficulty losing and sustaining any loss for matter for the past several months. I have lost virtually no weight in almost six months. I completed some additional blood work in the past couple of weeks since my doctor suspected some type of hypothyroidism given my symptoms. All of the levels came back normal except for T3 uptake being low, vitamin d deficiency, and testosterone less than 200 ng/dl.

We did an RMR test that came back with at 1450 calories per day at rest (The RMR of a 120 pound, 5ft. tall woman). With exercise and other activities, that brings my TDEE to about 1800-2000 calories per day at the most, 3000 less than the Scooby Calculator--I suppose this is what the problem is--trying to create a deficit within this framework. My doctor does not know why a 6ft tall 30 year old man that weighs nearly 300 pounds without a serious thyroid disorder has such a low RMR. I will be seeing and endocrinologist at some point in the future. This probably explains how I gained 100 pounds over the years on a 2000 calorie diet when I was largely sedentary.

I plan to keep my calorie intake at 1700 per day to see if that stabilizes my weight. I now understand that a 1000 calorie deficit per day is not attainable for me, so I will adjust upward to something more like 1/2 pound per week and try not to gain any more weight. I think 1700 calories a day is livable for the foreseeable future.