Some years back William Duffy wrote a book titled Sugar Blues that explains all this and more in fascinating detail. Most health food stores carry it. And read the label when you buy the high-protein food bars in the health food stores. Many contain sugar and lots of them are chocolate covered. If refined sugar had been discovered in this century, it would by a controlled substance, just like heroin or cocaine.
Sugar is highly addictive.
Read the labels on the packages and weep. He was half right. All tobacco in America is sugar-cured. This is a tricky subject. A lot of us just can't quit eating white flour products and live happily ever after.