The added ingredient, or flavor component, is subtle, she emphasized, so a person would not notice any appreciable difference in taste.
Her study cited the common-sense fact that solid foods are more filling than liquids, and attributed that in part to solid foods’ more-complex aromas.
As a practical application, she cited the example of yogurt, saying the fermenting conditions could be changed to make the texture thicker, releasing more complex aromas, and the taste would not be affected.
Another example, she said, involves the familiar smell of strawberries.
“If you add a natural strawberry aroma, you probably have a more complex aroma and feel more satiated,” she said.
Trials to date only have been done on a limited scale, and longer trials are planned.
Her team’s work does not represent a solution to the problem of obesity, she cautioned, but might help people “who eat too much and too often.”
Natural ingredients such as fiber added for health reasons also can create fullness, as can less beneficial ingredients full of carbohydrates or saturated fat, found in a lot of processed food, John Finley, a professor of food science at Louisiana State University, said in an interview.
The fullness factor doesn’t always stop people from eating too much, he said, since they may need the calories. Likewise, “It would be an oversimplification to say ‘Because something smells good, I won’t eat as much of it.’ ”
“What this research says is that a very complex set of aromas tends to be more satisfying,” he added, citing the comparison of a fresh homemade meatloaf with a frozen meatloaf meant for the microwave.
The homemade version “brings out a lot of volatile characteristics” — the kind that creates good aromas.
“The next step is to understand more details; to see how a fully developed meal impacts your total sensory experience, and see if it does actually have an effect,” he added.
Mr. Finley said the research reflects a common-sense view that the feelings of satisfaction can be produced by sensory stimuli that don’t involve actually eating food.
“You need to look at the visual effects as well,” he said. “Go to a nice French restaurant, and you typically get a presentation of delicious-looking food that is like a bouquet. They [chefs] work really hard balancing aroma and flavor to get a great experience. You get this, and you don’t have to eat as many calories.”