(WECT) - A lot of people worry about eating too much during the holidays, but what you eat is as important as how much you eat.
Volumetrics is based on the fact that people love to eat. If given the choice between eating more and eating less, you'll probably take more almost every time.
Okinawans tend to eat more food than Americans, but are often thinner and live longer. In fact, Okinawa has more Centenarians per capita than anywhere on the Earth.
Despite eating a greater volume of food, they are consuming fewer calories, because much of their diet consists of fruits, vegetables, tofu, and soup (all foods that contain a lot of water).
They also follow a tradition called Hara Hachi Bu, which is pushing away from the table when they're only 80% full.
"So, you're starting the day on the run. And you get a typical breakfast. For 400 calories, you only get three quarters of a cinnamon roll," said Penn State Professor Barbara Rolls.
Rolls studies the way Americans eat. She said Americans are eating too much fast food, or food that is "calorie dense."
A burger and fries, for example, is mostly fat, protein, and carbohydrates. Fat is 255 calories per ounce. Carbohydrates and protein are each 113 calories per ounce.
Fruits and vegetables, on the other hand, are mostly water and fiber. Fiber averages 57 calories per ounce and water is 0 calories.
Rolls thinks we should eat less "calorie dense" foods and eat more fruits and vegetables instead.
"Volumetrics helps you feel full on fewer calories. We know that eating foods that are lower in calorie density helps to fill you up," said Rolls.
While the hook of volumetrics is clever, it essentially boils down to the sensible diet that any nutritionist would recommend: lower-calories, lower-fat, with lots of vegetables and fruits.
For more on the volumetric eating plan, click here.