It has been said that the results you get from a fitness program are a 3 way split: 1/3 genetics, 1/3 training and 1/3 nutrition. Personally, I believe that training and nutrition are more important than genetics.
For one thing, any individual can improve from any starting point, and there is no such thing as being genetically disadvantaged when it comes to health and fitness. It doesn't matter whether your parents were Olympic sprinters or couch potatoes - it's up to YOU to make the most of YOUR body and YOUR life.
So if at least (or in my opinion, more) 33% of your training results are determined by the kind of fuel you put into your body, it's only logical that you should try to give yourself as much of an advantage as possible. Everyone has different tastes and preferences when it comes to food, not to mention schedules and energy requirements, so there is no such thing as "one diet fits all". Nevertheless, there are a few standard pointers that are universally applicable:
I get asked questions all the time about how much fibre is necessary, what the scoop is on carbohydrates - are they really fattening? - whether dairy products are a no-no, and what kinds of supplements people should be using. Send me your nutrition questions! I can help you understand food better and make it part of your healthier living strategy. Just address your questions to me at: firstname.lastname@example.org.