I've done a couple of 300k brevets since I went primal (and a load of 200s) and have found that by keeping my HR < 70% I just havent needed to eat so often, and when I do eat then primal meals (meat + veg) are perfect. The only time I need carb heavy stuff or energy drinks are if I've pushed it too hard.
I'm making progress again now thanks, with two changes, one to diet, one to training -
Mixing up the training a bit with some steady 80% of maxHR turbo sessions, with some 20-30 miles road rides on hilly courses, where I'm at 80% most of the time, but bursts up to 90% on hills.
Diet wise still largely primal, but taking carbs before and during rides.
I feel a lot stronger now, my weight went up to start with, then levelled off, then has started to track down a little again. But I think I'm going in the right direction, because I feel so much better on the bike and so I guess some pounds will have to come off in due course.
30 minutes of the cycling the really help to burn the calories of the human body. Cycling is effective not only for the upper body but it
also helpful for the lower body fitness.