Sugar makes most people feel weak and foggy. It's toxic and carcinogenic.
Safe starch, however, eaten in the right context makes those who have not rendered themselves severely metabolically damaged feel strong and energised.
The 'carb' label is just as simplistic as the 'fat' label.
F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.