Hi Dan,
This may be overly obvious, but try drinking Hammer Sustained Energy or Perpetuem as you ride, i.e. don't "wait for lunch" but rather keep the nutrition going into your system on a fairly consistant basis. I use one bottle of Hammer, one of water, and rotate those as you ride.
Or, on doubles, I use a Camelback and put the Hammer mix in there (plain water in the bottle), which works fine (but requires a detailed cleaning of the Camelback after the ride!). Just FYI I rode 9 doubles last year, but the only "quite hard" one was Mt. Tam.
Rick / OCRR