Last year I was told by a cardiologist to change my diet away from meat, dairy and carbs. My diet is now high bran, fish, soy and low meat and low fat. From what I have been reading recently, mostly because I notice it more maybe, is that soy is a mayor reason why the Japanese have less heart attacks, live longer and have less prostate problems and less hair loss than the west. I take soy with my all bran bud cereal every morning now.
And, to cut a long story short. I still lost a lot of hair in the last year. I think once the gene for hair loss is switched on, it's difficult to stop with food and exercise alone.
If your not already taking Propecia or Avodart, now would be a good time to think about them. But as with everything, get professional advice, and do your own research, which it looks like your already doing.