Simple obesity solution suggests choosing meals that slow eating

A Japanese study has found that choosing the right type of meal rather than eating order changes chewing and meal duration. This offers insights on preventing obesity and highlights the importance of healthier eating habits.

“Eating slowly is widely recommended for obesity prevention,” says lead researcher Professor Katsumi Iizuka at Fujita Health University. “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 study published in Nutrients also discovered that men tend to eat faster and chew less than women, but the overall trend remains consistent. It also suggests that obese people opt for ultra-processed, easy-to-eat foods like pizza, which may result in faster overeating.

Comparing meal and chewing time

Worried about rising obesity rates, the researchers sought simple and practical ways to encourage healthy eating habits. 

Although eating slowly remains a challenge, Iizuka’s team studied 41 adults, 18 males and 23 females, aged 20 to 65, who consumed three test meals over many weeks.

Meals included pizza, hamburger steak bento, which was eaten with vegetables first, and the same bento, which was eaten with vegetables last.

The team used a wearable chewing sensor and video analysis that measured meal duration, number of chews and bites, and chewing tempo.

They found that those eating pizza ate faster than those eating bento, having a shorter meal and fewer chews, regardless of whether vegetables were eaten first or last. 

The bento meals with rice, vegetables, and meat, consumed using chopsticks, had longer meal times and more chewing.

All meals were closely matched for calories, protein, fat, and carbohydrates to assess the impact of meal type and sequence on eating behavior (Image credit: Iizuka).Researchers were surprised that the number of bites was consistent across meal types and chewing tempo showed little but statistically significant differences.

“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,” Iizuka explains.

Importance of learning how to chew

Men were found to eat faster and chew less than women, but the overall finding applied to men and women.

Additionally, researchers saw older people eat faster than younger ones, likely because of dental health or chewing ability. They also saw no link between having a higher body mass index and eating faster. However, obese people gravitate to ultra-processed and easy-to-eat foods.

The researchers say the brain’s natural rhythm controls chewing tempo and is less likely to change. However, the number of chews and time spent on them can change with meal type. 

They suggest eating slowly, increasing chews and smaller bites to extend mealtime, which also helps 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 Iizuka.

Earlier research found that the order of eating vegetables, protein, or fat, combined with slow eating, improved postprandial blood glucose trajectory and decreased insulin secretion in people with or without type 2 diabetes.