Race day nutrition - plenty of easy to digest sugars, some sodium and potassium and other trace minerals if it's long and/or hot race, doesn't disagree with my gut, and a taste that is at least somewhat palatable
Everything else - I try to stick mainly to stuff that doesn't really need a label. Fish, good quality meat, lots of veg, try to get most of my carbs from brown rice or other wholegrains. I try to roughly match my carb intake to what I'm burning off in training. I.e. on a day when I do no training I'll try to have very few carbs, but on a day when I'm doing 2 hours of training and burning maybe 1500 calories off then I'll replace most of those calories from carbs. I rarely have sugary sports nutrition in training though - I find I don't need it unless I'm training >2 hours with a fair bit of intensity and no breaks where I can take on other nutrition, I think it's overpriced, it mostly tastes pretty awful, and it rots your teeth. So I mostly train on water and then replace the carbs afterwards or mid-ride. Would much rather get sugary calories from a slice of cake or a flapjack than from a sickly energy gel or drink.
And of course there are days when all of this goes out of the window. I have a sweet tooth and I like a beer or wine, which for me is one of the bonuses of training a lot in that I can have a few drinks, a piece of cake or a few scoops of ice cream and just burn it off. Everything in moderation, including moderation, is a good motto!
This guy has it figured out.
Race day nutrition for me is liquids only (after a pretty bland, oatmeal and banana breakfast). No matter what distance I am racing, I try to drink approximately 400 calories of electrolyte/carb drink in the 90 minutes before the gun goes off, making sure I am finished at least 15 minutes before start. If the race is short then I am tanked up and only need a little bit of water. Longer races, I will try to consume 4 to 6 calories/kg/hour of the same electrolyte/carb drink while on the bike and then try to take in 1-3 calories/kg/hour of whatever liquid they are offering on course while on the run. Supplement with whatever water you need depending on conditions and this should keep you racing to the finish line.
I used to race with bars, gels and other solids and invariably, when I got to about the half way point of the run my gut would start to get unhappy. Since switching to the all liquid plan I have done dozens of races without any GI upset. It works for me.
Like cartsman, I am not using a whole lot of sugary drinks while training. I am out of the IM business for now, so it is rare that my training takes me so far that I need calories. If I am setting out for something that will take me two hours or more I always throw a couple gels in a pocket as a rescue plan but it is not that often that I need them. This way I can splurge a little bit on custom Infinit for racing and it will last me all season, sometimes longer.
Daily, I try to eat 10! servings of fruits and vegetables every day. Fill in with some lean proteins. Splurge on cake or a donut if the mood is upon me. Split a beer with my wife with dinner. Life is short. We train hard. Food is meant to be enjoyed ;-)
None of the secrets of success will work unless you do.