people say fat doesnt boost testossterone levels. and there are actually some studies that show it has a negligeable effect.
BUT...!!!
try out a high fat diet
youll notice the difference!
but no, not lower carb, RIGHT carbs. fruits and veggies are terrefic carbs. not too much veggies though! too much fiber can lower testosterone.
OH, and the RIGHT fats as well. monounsaturated and cholesterol-containing saturated fats are best for testosterone. NOT polyunsaturated, trans fats
the way you workout can effect it as well
full body workouts, H.I.T. style twice per week. thats a good way of doign things