Why What You Eat Matters More Than How You Eat It

Japanese study finds meal type, not eating order, influences chewing and meal duration—potential insight for obesity prevention strategies

A study from Fujita Health University reveals that meal type, rather than meal sequence, significantly impacts how long people eat, how much they chew, and how fast they chew. Bento meals—typically eaten with chopsticks—led to longer mealtimes and more chewing than fast food like pizza. This is the first study to isolate meal structure as a key factor in eating speed, offering simple, practical strategies to combat obesity and promote mindful eating.



In a society facing rising obesity rates, it is more important than ever to find simple and practical ways to encourage healthier eating habits. One common suggestion for supporting digestion and weight control is to eat slowly. However, many people still find it challenging to incorporate this practice into their daily lives. To overcome this struggle, a team of researchers led by Professor Katsumi Iizuka from Fujita Health University, Japan, offered a clear and simple answer, stating that the type of meal we choose may matter more than the order in which we eat it. This study was published in Volume 17, Issue 9 of the journal Nutrients on May 3, 2025. “Eating slowly is widely recommended for obesity prevention,” said Prof. Iizuka. “But people often don’t know how to implement this advice. Our study shows that simply choosing the right type of meal—such as a bento instead of fast food—can naturally extend meal duration and encourage more mindful eating.” The research was also actively supported by Kanako Deguchi from the Department of Clinical Nutrition, Fujita Health University.

The team studied 41 adults (18 males and 23 females, aged 20 to 65) who consumed three test meals over several weeks: pizza, a hamburger steak bento eaten with vegetables first, and the same bento eaten with vegetables last. Researchers used a wearable chewing sensor and video analysis to measure each participant's meal duration, number of chews and bites, and chewing tempo. The findings were striking. Participants ate pizza significantly faster than bento, with shorter meal durations and fewer chews, regardless of whether vegetables were eaten first or last. In contrast, the bento meals—consumed with chopsticks and consisting of individual components like rice, vegetables, and meat—promoted longer meal times and more chewing. Surprisingly, the number of bites remained consistent across meal types, and chewing tempo showed only slight but statistically significant differences.

The study also looked at differences between men and women and found that men generally ate faster and chewed less than women. However, the overall trend was the same in both groups—bento meals took longer to eat and required more chewing. Older participants tended to eat faster than younger ones, which could be due to changes in dental health or chewing ability. One might expect that individuals with a higher body mass index (BMI) would eat faster, but the study found no association between BMI and meal duration, challenging common stereotypes. Instead, the researchers suggest that people with obesity may gravitate toward ultra-processed, easy-to-eat foods like pizza, which could lead to faster meals and overeating.

Prof. Iizuka explains, “One key factor affecting meal speed is how the food is served and eaten. Bento meals are served in small portions that need to be picked up with chopsticks, which slows down the process. In contrast, pizza is eaten by hand and is often designed to be eaten quickly. This difference in serving style plays a big role in how fast people eat.”

Scientists also point out that chewing tempo, or how fast people chew, is controlled by the brain’s natural rhythm and is less likely to change. However, the number of chews and the time spent chewing can vary based on the meal type. Eating slowly by taking more chews and smaller bites helps extend the meal duration, which is linked to better digestion and weight control. “If we want to help people eat more slowly, we should focus less on telling them how to chew and more on helping them choose meals that require slower, more deliberate eating; this could be a simple yet powerful tool in our fight against obesity and related diseases,” says Prof. Iizuka.

In conclusion, this study highlights that making simple meal choices—like opting for traditional bento-style meals over fast food—can naturally slow down eating, increase chewing, and support healthier habits. As obesity rates continue to rise, focusing on what we eat, rather than just how we eat, may be a practical and effective step toward better nutrition and long-term well-being. Simple habits like these could make a big difference in promoting healthy eating behaviors.

Reference

Title of original paper

The Meal Type Rather than the Meal Sequence Affects the Meal Duration, Number of Chews, and Chewing Tempo

Journal

Nutrients

DOI

10.3390/nu17091576

 This research received funding from the Suzuken Memorial Foundation (23--003).