I've come to the conclusion that the carbohydrate curve is not right. I do not think you can obtain the kind of obesity depicted in that cartoon of Ken Korg on carbohydrates coming from roots, tubers and fruit. To end up with diabesity like Ken Korg you have to eat white flour, corn/soy/canola/trans-fats and processed foods. You would have to eat too many calories to reach really high levels of carbs from roots, tubers and fruit and might gain some weight if you aren't active enough to burn those calories off, but the fat you gained wouldn't be that diabesity-type fat.
That's just a suspicion I have as I no longer worry about how many carbs I consume (or don't consume) and never see any difference. What does result in a difference is if I just eat less period, and if I stay away from grains, seed oils and processed foods. Eat less = lose some weight. Avoid grains, seed oils and processed food = feel awesome and healthy.
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
Starting squat: 45lbs. Current squat: 160 x 2