Satisfaction no longer an excuse

You've probably heard that you should eat slowly to give your body time to signal you when you're full. This is called "alimentary alliesthesia" (you don't need to remember it; there won't be a quiz). Another mechanism that helps your body control how much you eat is called "sensory-specific satiety". This term describes how eating a lot of the same kind of food will make it taste less good to you over the short term.

There's been a theory floating around for some time now that essentially says that people who are overweight experience those two bodily mechanisms for weight control in a way that's different from those who are normal weight. In short, an overweight person's body doesn't tell them to stop eating the same way a normal weight person's body does.

In the latest issue of the International Journal of Obesity (2007;31:987-995) there's an interesting study which attempts to verify or disprove this theory. The scientists recruited 144 adults (half men; half women) in good general health and with a stable body weight for the previous six months. The Body Mass Index for the participants, however, ranged from 16.9 (underweight) to 38.6 (very obese). The participants were then assigned to one of six groups based on their preference for one of six foods: cucumbers, tomatoes, pineapples, bananas, peanuts or pistachios.

The actual testing was very simple: Before the test, the participant was asked how hungry they felt and whether they had an appetite. They were then given unlimited amounts of the preferred food and were asked to eat until they felt they were finished eating (had reached that "sensory-specific satiety"). After the last bite of the food, they were again asked the two questions. How much they ate in weight, how much in calories, and how long it took the subject to eat were all measured.

The researchers found that the overweight subjects ate an insignificant amount more in weight and volume than the normal weight subjects. However, overall there was no relationship between Body Mass Index and how many calories the subject ate, regardless of which food they ate. Sensory-specific satiety appeared to be the same across not just BMI levels, but also age and gender.

What this means for you

The take home message here is that those who are overweight will feel just as satisfied as normal weight people when eating the same food. So eating good food that's good for you will be just as satisfying for those who are overweight as it is for those who are normal weight.

First posted: June 27, 2007