Thanks for the answers. Let me be clear, I'm not looking for a reason to increase my carb intake, just asking if there is a valid healthful reason to periodically do so.

Cookies and other baked sweets are my crack and I'd just as soon avoid them forever, but if eating a few sweet potatoes or beets, maybe a small bowl of coarse rolled or steel cut oats for breakfast, for say a weekend once a month actually had benefit, I'd consider it. I've found lots of anecdotal "evidence" and opinions on carb cycling, but not much hard science.