A thick and creamy product might affect satiety and weight management more positively than a thin and watery product. That is, provided the two products contain similar nutrients and calorie levels, says Martin Yeomans, Ph.D., a professor of experimental psychology at the University of Sussex in Brighton, United Kingdom.

Sensory elements impact satiety just like nutrients do, he said in a July 18 presentation at the Institute of Food Technologists’ annual meeting and food exposition in Chicago.

“You can start altering consumer behavior by integrating sensory and nutrition,” Dr. Yeomans says.

While not formally trained in food science, Dr. Yeomans says he has spent 30 years investigating appetite and sensory effects.

He says in one experiment people ate breakfast. Three hours later they drank a beverage such as a yogurt smoothie. The beverages were different each day. They could have one of three sensory characteristics. For example, tara gum may create a thicker, creamier beverage. The beverage also may have energy/calorie content of either 79 calories or 279 calories. Results from the study found people could not tell the differences in the calorie content of the products, but they could tell the sensory differences.

At lunch, people were given pasta and tomato sauce. As expected, they ate less lunch on the day they drank extra calories in the beverages. A gap in calories consumed at lunch appeared after drinking beverages with the same nutritional/calorie content but with different textural qualities.

After drinking a thin and watery beverage, people did not eat as much lunch.

“Your brain isn’t thinking about the hidden nutrients,” Dr. Yeomans says of the thin and watery beverage. “But if it’s thick and creamy, your brain responds to the hidden nutrients, and you alter your behavior. So a satiety product is one that generates strong expectations and delivers nutrients.”

He added umami may act as a sensory-satiety cue for protein. When an umami flavor is in a food, the brain expects protein.

“Umami makes the protein more effective,” Dr. Yeomans says.

He gave another example of monosodium glutamate (msg) providing an umami effect in soup. People in an experiment did not overeat in a two-course lunch after eating soup with msg in the first course. The outcome was not the same for people who ate soup with no msg.

The droplet size of oil in oil-fat emulsions, without any alteration in fat content, also may change sensory experience and consequently satiety expectations. Tiny droplets of oil may create a creamy mouthfeel and lead to greater satiety.

In summary, “consumers have clear and measurable expectations about what products will do for them,” Dr. Yeomans says.

“This is big stuff,” he says. “If you apply that to a diet, it’s the difference between people putting on weight and people staying with the (diet).”