Many people "graze" throughout the day, eating many small meals spaced every couple of hours or nibbling continuously throughout the day. They reason that grazing pre-empts the drop in insulin and blood sugar that occurs during longer periods of time between meals that can trigger greater appetite. They argue that grazing leads to lower calorie intake and perhaps weight loss.

But there are fundamental flaws in the notion of grazing, adverse effects that might even contribute to high blood...