How often do you finish a 10-minute meal feeling full only to experience bloating a half hour later? If you are over forty, you will probably remember putting less food on your plate, rarely having seconds, feeling bloated only one meal per year (Thanksgiving dinner), yet never leaving the table hungry.
Fifty years ago, people prepared less food, put less food on their plates, and ate less, yet most left the table satisfied because meals were family events that generally lasted forty-five minutes to an hour. Meals used to be the high point of the day. We may not have eaten our food any slower, years ago, but we did linger around the table.
Today, families are smaller and we have many more entertainment options. It is no surprise that we seem to eat faster and savor our food less. And because we cannot feel satisfied in ten minutes, we have substituted a sense of fullness in our stomach for the satiety that comes later.
There are several problems with using fullness to signal adequate food intake. First, the stomach is a muscular pouch, which can stretch to accommodate more food, so a full stomach can mean different amounts of food. Second, many foods pack a lot of calories into a small volume (high caloric density) so a full stomach might hold more calories than we need in a day. Third, after eating till we are full, the arrival of satiety a half hour later transforms feeling full into an uncomfortable sense of feeling bloated.