Carbohydrate Overconsumption Leads to Caloric Excess and, in a Chain, to Many Chronic Diseases

Grace "I strongly agree. So many of the diseases of modern people come from consuming far too many calories. The classic example is metabolic syndrome. 'Metabolism' really means energy metabolism. Overweight, diabetes, hypertension, kidney disease, abdominal obesity — they all share the same cause. The body has stored more calories than it needs, and that excess itself becomes a kind of toxin."

Dr. Lee "Right. Grace lived in the U.S. for over thirty years, earned her registered dietitian credential there, and worked as a hospital dietitian for thirty years. So she may understand the seriousness of diseases caused by nutrient excess even better than the rest of us. Even fat cells, which are technically nutrient stores, will release toxins and inflammatory hormones once they exceed a healthy load. We have come to understand the cause of nutrient excess; the remaining problem is that we have not reached consensus on how to control caloric excess. To put my conclusion plainly: if you eat lots of carbohydrates, weight management becomes very difficult. There are several reasons. Carbohydrate intake stimulates the appetite center in the hypothalamus, making you want to eat even more. Carbohydrate intake also raises blood glucose, which triggers a large insulin release (see Figure 5-1). After hyperinsulinemia sets in, glucose is driven rapidly into cells and blood sugar plunges into hypoglycemia. You then eat ravenously again. High blood sugar, high insulin, plunge — the cycle repeats like a roller coaster, and the pancreas is gradually exhausted. Cells respond by reducing the number of glucose receptors, refusing further glucose uptake — insulin resistance, or glucose intolerance. Rising insulin also makes the body inflammation-prone, and it promotes lipogenesis — the conversion of carbohydrate into fat. So merely increasing carbohydrate intake produces different side-effects in different tissues across the whole body. In more technical language we call this tissue specificity: a single hormone produces different outcomes in different tissues."