Field Notes

Exercise, More Than Diet, Key to Preventing Obesity

Researchers have credited two factors—metabolism and gut microbes—as key players in the fight against obesity. However, there’s an ongoing debate about whether exercise or diet better promotes metabolism and healthful shifts in gut microbes. New research from the University of Missouri (MU) confirms exercise plays a significant role in the fight against obesity.

“Some have claimed that exercise may not play a significant role in weight loss, as exercise can increase appetite, resulting in greater food intake and potentially reduce activity throughout the day,” says Victoria Vieira-Potter, PhD, an assistant professor of nutrition and exercise physiology at MU. “The purpose of this study was to look at exercise independently from weight loss and to determine other metabolic benefits associated with physical activity. Our team aimed to tease out what effects on adipose, or fat, tissue were due to weight loss from diet, and what could be attributed to exercise.”

Vieira-Potter and her research team divided young rats prone to obesity into three groups to study the impact of exercise on their metabolic function and fat tissue. All three of the rat groups were fed a high-fat diet. Two of the groups were sedentary, while the third group was able to exercise using running wheels. Of the two sedentary groups, one was allowed to eat as much of the high-fat food as they wanted, while the other group was fed controlled portions of the food in order to match the weight reduction caused by exercise. The exercising rats were allowed to eat as much as they wanted.

Several weeks later, all rats were moved to specialized cages where researchers could measure their metabolism and physical activity. Researchers found the sedentary rats with unlimited food access were obese, unlike the sedentary rats fed a reduced amount of the same diet and the rats that exercised, which was expected. Notably, the researchers also found that the exercising rats were metabolically healthier than both of the sedentary groups, and they developed different gut microbes than the other groups, despite eating the exact same amount of food as the sedentary group with unlimited food access.

“Overall, the exercising rats had higher metabolic rates, were more active even when not running on their wheels, and experienced shifts in their gut microbes, perhaps putting them in a better position to avoid future weight gain compared to the other groups,” Vieira-Potter says. “These findings confirm that exercise is an important component of overall health and is critically important in the fight against obesity, especially during the juvenile period.”

— Source: University of Missouri Health


Encouraging Healthful Food Selection in Food Pantries

Grocery stores have long deployed insights from behavioral economics to influence the purchase of targeted foods. But can similar tactics work in community food panties to nudge clients to make more healthful food choices?

Researchers from Cornell University's Food and Brand Lab have uncovered ways to do just that. Prioritizing the placement of more healthful options and keeping foods in their original boxes significantly impacted the selections made by food pantry clients, revealing new tactics to improve food security for low-income populations.

“Food pantries offer a unique opportunity to nudge those most at risk of hunger to select more nutrient-dense foods,” says lead author Norbert Wilson, PhD, a professor at Auburn University and a former visiting professor at the Charles H. Dyson School of Applied Economics and Management, where he conducted the research with Cornell University professors David Just, PhD; Brian Wansink, PhD; and doctoral candidate Jeffery Swigert.

Low-income populations that most often frequent food pantries also suffer disproportionally from the most severe food-related health problems, including obesity and nutrient deficiency. Food pantries offer access to food while allowing patrons to choose what they want based on availability, a method that preserves dignity but can limit options for nutrient-dense foods.

The researchers placed protein bars in the dessert section alongside less-nutritious foods like cakes and brownies and observed the behavior of 443 visitors to a New York State food pantry. The findings, published in the Journal of Public Health, show that applying easy, low-cost food marketing techniques in pantry displays can lead more clients to select healthful foods.

To nudge selection of the bars, the researchers implemented two techniques. First, they placed the bars so they appeared first in the dessert section. Prioritizing the bars first increased selection by 46% compared with when the bars were placed at the end of the section.

Next, the researchers kept the bars in their original boxes instead of repackaging the individually wrapped bars in clear plastic wrap. Keeping the product in its original packaging removed the stigma of receiving the product from the food pantry, according to the researchers, and resulted in an increased selection by nearly 59%.

“Food pantries offer choice, much like grocery stores and cafeterias, and research has shown that choices are tied very closely with our environment,” Just says. “For this reason, low-cost techniques that increase visibility and convenience of healthy foods are effective in increasing selection of these target foods.”

When both techniques were implemented—placed first in the section and kept in original packaging—the protein bars were even more popular. The study findings show food pantry organizers that these easy-to-implement strategies can increase healthful food choices among pantry clients.

“While food pantry organizers receive a mix of products, some more healthy than others, this study shows that they can help nudge clients to select those foods that are on the healthier side by making them more convenient—placing them first in line—and appealing, keeping them in the original packaging,” says Wansink, a professor and director of the Cornell Food and Brand Lab.

— Source: Cornell University