Erik says it right---
"Those well-fitted and designed packs, like we see described/claimed about Dan McHale and Dick Kelty's products [ :) ], sure pay off and resolve these issues for many of us."
As I was saying about my Mystery Ranch pack. Designed to haul weight with attention paid to physical comfort.
On my last 18 day trip my food load was almost identical to Jardine's recommendation of 2.5 lbs a day---45 lbs.