In reply to BusyLizzie:
As someone who has recently and comprehensively bombed on an ultra due to lack of food, the following works for me...
Eat a good fat and fuel filled brekky as close to start time as possible. Porridge isn't enough. If there is going to be more than 2 hours from breakfast to start then eat continuously through that time. Pork pies are good, ditto Baby bels, but only in winter. In summer the top ups need to be more heat resistant, such as bars, sarnies, etc. Ditto drinking as much as you can reasonably stomach.
Unless you are really going to push it, keep eating through the first 10 miles as you run. I find its a good way of keeping my uphill running to a sensible pace as eating and breathing require a certain low speed and equilibrium!!
Find the salt at the food stations. Crisps, chips, salty nuts, doesn't matter, but just make sure you get some. Gels don't work for me. I can puke for Britain anyway while running on normal food, without that gloopy sugary stuff. After 25 miles or so I feel less and less hungry, but if I have got it right I am normally fed and watered well enough to run a very long way by then.
Of course although I "know" all this works for me, But I have trouble remembering it. So when it gets forgotten it all gets rather messy (sick!).