Snacks provide, on average, about a quarter of most people’s daily calories. According to the National Institutes of Health, nearly one in three adults in the United States is overweight and more than two in five is obese. So researchers at Penn State’s Sensory Evaluation Center are investigating how Americans can snack more wisely.
The latest study conducted at the center, housed in the College of Agricultural Sciences, investigated how eating behavior changes when consumers are served a sauce alongside a salty snack. The findings, available online now and to be published in the November issue of Food quality and preference, They suggest eating more, a lot more. Chips and salsa together resulted in a 77% higher caloric intake and a faster rate of total intake compared to the control group that ate only chips and no salsa.
However, there was no difference in French fry consumption, said study corresponding author John Hayes, a professor of food science and director of the Penn State Sensory Evaluation Center.
“The most surprising results of our study are that people did not eat fewer chips when there was salsa, but rather they ate the same amount of chips, plus salsa,” she said. “This lack of compensation means that adding salsa to chips can substantially increase total energy intake without people realizing it.”
Intuitively, many people would think that if we add something extra to a snack, such as sauce, people will compensate and eat less of the main food, Hayes explained.
“But our research shows that’s not the case with chips and salsa,” she said. “Our participants consumed the same amount of chips regardless of whether salsa was present, which translated into a much higher energy intake when salsa was available.”
The study, led by research assistant Madeline Harper, who recently graduated from Penn State with a master’s degree in food science, evaluated 46 adult participants. On two visits to the Sensory Assessment Center, they were served 70 grams of ranch-flavored potato chips, or about 2.5 servings, with or without about a third of a cup of ranch sauce. Participants ate as much as they wanted.
Their intake was measured and all feeding sessions were videotaped, with data on the number of bites taken and the time spent actively feeding recorded. The researchers used this information to calculate measures of “dietary microstructure,” including feeding rate and bite size.
Harper suggested that the higher intake of chips and salsa was facilitated by a larger bite size resulting from the inclusion of salsa. On average, per eating session, participants consumed 345 calories from chips and salsa compared to 195 calories from chips alone.
The study was novel, Harper noted, because little research has been done on the effect of external sources of oral lubrication, such as sauces, on the oral processing of salty snacks.
“It is clear that it influences food intake, especially when snacking between meals,” she said. “However, in the case of this chips and salsa snack, the greater intake resulting from the inclusion of salsa may have been facilitated by a larger overall bite size, rather than a faster rate of ingestion of chips.”
While snacks are an important source of energy in the typical American diet, they remain understudied, Hayes said, adding that understanding eating behavior around snacking is crucial to addressing the problems of overeating and obesity.
“This research opens up new avenues for exploring how the physical properties of food can influence our eating habits and ultimately our energy intake,” she said. “If we can get people to slow down, we can influence energy intake without giving up the pleasure of food.”
Paige Cunningham, a postdoctoral researcher in Penn State’s Department of Food Science and Department of Nutritional Sciences, contributed to the research.
The U.S. Department of Agriculture’s National Institute of Food and Agriculture supported this research.