I've been training for a marathon am just now up to 12 miles. It feels like I've hit a brick wall, though, when I reach 12 miles. I don't run very fast -- about 12-minute miles on long runs -- so when I get to 12 miles I've been running for about 2 and a half hours. I probably eat about 40 carbs a day, but on these long runs sometimes I have that very weak, no energy feeling like I've been fasting. I don't eat fruit, but I do eat low-carb bread (5 grams a slice, 2 slices a day maximum). The short runs are wonderful and I can run them faster. I used to do the short runs on 20 carbs a day with no problem. While I was a competitive middle-distance runner 10 years ago, I don't know anything about marathon running. I've been reading on marathons but all of the training programs seem geared towards a high carb diet. I know everyone's body is different, and it seems that I need more energy, but I don't want sugar or high-carb products to be a part of my life. Have you found anything particularly helpful (i.e. eating more vegetables than meat, less dairy, etc.)? Thanks so much!

Liv