I found this article to be pretty good general advice. I’m 41 and have been a slave to trying to build a lean, muscular physique since I was 17. That is a lot of experience with trial and error and I have found this article to be a good summation of the situation. Age is a MAJOR factor, however. After a diet my strength dwindles significantly so a couple of years, like always, I would eat more to re-coup that lost strength/muscle. I have really noticed in the past few years that still happens but now the fat comes back very easily because of the age. Last time I did my same old routine, increased my calories/food intake (it didn’t seem like I was overeating) and probably gained 30 fat pounds. And I was hardly stuffing myself either. I am ending another diet phase and my approach to bouncing back my strength will be eating only slightly more. Pounding the calories worked well when I was younger but getting 30 pounds off now takes 8 months, not 2 months like it did when I was young.
The most commonly used AAS in medicine are testosterone and its various esters (but most commonly testosterone undecanoate , testosterone enanthate , testosterone cypionate , and testosterone propionate ),  nandrolone esters (most commonly nandrolone decanoate and nandrolone phenylpropionate ), stanozolol , and metandienone (methandrostenolone).  Others also available and used commonly but to a lesser extent include methyltestosterone , oxandrolone , mesterolone , and oxymetholone , as well as drostanolone propionate , metenolone (methylandrostenolone), and fluoxymesterone .  Dihydrotestosterone (DHT; androstanolone, stanolone) and its esters are also notable, although they are not widely used in medicine.  Boldenone undecylenate and trenbolone acetate are used in veterinary medicine .