The head of the Center for Obesity at the University of North Carolina has an interesting take on the relationship between liquids and weight gain. Read the full interview with Dr. Popkin here.
Q: Why did you organize a panel of experts to advise people about what to drink?
A: People don't understand that beverages are less satiating than solid foods. When you consume calories from beverages, you don't compensate by eating less food later on. Liquid calories don't register with our appetite controls.
Since we evolved getting our calories only from food, it makes sense from an evolutionary perspective that drinking water wouldn't limit your food intake. It would be dangerous if people were no longer hungry after drinking water, because they wouldn't consume enough food. We were built to have separate thirst and hunger mechanisms because the body needs both fluids and calories from food. Throughout evolution, fluids had no calories.
Paleolithic humans lived on breast milk and water. One to two thousand years ago, we started to consume beer and, much later, other alcoholic beverages. A few hundred years ago, when coffee and tea were introduced, people put a little sugar in them. Those were the major caloric beverages out there, along with some local juices off of trees.
We didn't really get many calories from beverages until the last century, when more sweetened teas and coffees, and then soft drinks, came in after World War II. So we are in a new world when it comes to beverages. We've really shifted over time.
