Do Eating Behaviors Affect Obesity?

Emerging evidence suggests that how you eat, as well as what you eat, can have an impact on obesity. Recent research showed that the number of chews and bites and meal duration can affect feelings of hunger and satiety and, by extension, how much food is consumed.

In a recent small study of women and men who ate a test meal of pizza, researchers in Japan assessed associations between meal duration and various factors including the number of bites and chews. They found that increasing the number of bites and chews and slowing the eating tempo with the use of a metronome, resulted in increased meal duration and the likelihood of consuming less food.

These strategies, and perhaps creating a slower eating environment by using calming music or rhythmic cues, “are easy, money-saving measures” that can potentially reduce food intake and help prevent obesity, suggested principal investigator Katsumi Iizuka, MD, of Fujita Health University, Toyoake, Japan.

Iizuka told Medscape Medical News that eating foods with different degrees of hardness may also increase the number of chews, as seen in a recent study of the effects of food texture on eating rate and energy intake.

“It’s also important to eat when the mouth is empty,” that is, swallow everything that’s in your mouth before taking another bite, Iizuka added.

Other recent studies have confirmed that extending meal duration can have beneficial effects on weight control. For example, a study of Spanish adolescents showed that those whose meals lasted longer had a significantly better body mass index z-score than those whose meals were of moderate duration. And a literature review found associations in both adults and children between faster eating speed and higher risks of developing adiposity, as well as metabolic syndrome or its components.

Additional Benefits

Eating more slowly could also have positive effects on digestion and nutrient absorption, Amanda Velazquez, MD, director of Obesity Medicine at the Center for Weight Management and Metabolic Health at Cedars-Sinai, Los Angeles, told Medscape Medical News.

“Chewing food thoroughly allows the digestive system to process the food more effectively, breaking it down into smaller particles and enhancing the activity of digestive enzymes. This could lead to better nutrient absorption,” she explained.

Furthermore, “slower eating might reduce the risk of indigestion, bloating, and other GI [gastrointestinal] issues since the stomach has more time to receive and process food in smaller quantities, which can also reduce the risk of overeating and acid reflux,” said Velazquez.

Jamie Mullally, MD, Division of Endocrinology and Metabolism at New York Medical College, Valhalla, New York, agreed that taking more bites and eating more slowly can aid digestion and nutrient absorption.

“Additionally,” she said, “it allows more time for the brain to register feelings of fullness, potentially leading to improved satiety signals.”

Mullally would like to test slower eating among patients on anti-obesity medications such as semaglutide and tirzepatide. “I’ve observed that [these] patients often experience more nausea when they eat too quickly or too much, and I believe the eating pace strategies…could be beneficial in preventing overeating and minimizing these side effects,” she explained.

More Helpful Behavioral Strategies

In addition to increasing the number of bites and chews, other behavioral strategies have been shown to slow eating and potentially improve weight loss and weight-loss maintenance.

Both Velazquez and Mullally suggest mindful eating. While there is no universally agreed-upon definition, the method essentially involves eating more slowly and without distractions (eg, television or smartphone use), focusing on the meal, and staying aware of the body’s hunger and fullness cues.

A recent narrative review found that although the research suggests that mindfulness-based interventions may be beneficial for weight management as well as disordered eating, effects may vary depending on the individual and/or the eating context. The authors wrote that future research might point to a more personalized approach to mindful eating that could maximize benefits.

Smaller portions and more frequent meals throughout the day are two more strategies that could prevent overeating and help manage caloric intake, Velazquez said. “Emphasizing nutrient-dense foods (like fruits, vegetables, whole grains, and lean proteins) also can help ensure people are feeling satisfied and getting the nutrients they need, without excess calories.”

“Since satiety is a complex mechanism involving gastric distention, intestinal hormones, and relaying messages to the brain, anything that can prolong meal duration could be helpful to complete these pathways prior to eating past satiety,” said Susan Wolver, MD, associate professor at the school of medicine at Virginia Commonwealth University (VCU), Richmond, Virginia, and medical director of VCU Health’s weight loss clinic.

“There are many ways to prolong meal duration” in addition to slowing down chewing,” she told Medscape Medical News. “These include sitting down at a table to eat, putting down your fork between bites, and drinking water while eating.” She also advocated mindful eating and avoiding distractions.

Beyond Eating Behavior

For adult obesity treatment overall, Wolver recommends weekly weighing, learning to read labels, keeping the environment free of trigger foods, and “working on a healthy relationship with food, trying not to assign values such as ‘good’ and ‘bad,’ as all foods can be part of a healthy eating plan.”

Velazquez added that extreme food restriction, irregular eating patterns, and eating at night are potentially harmful strategies. “It’s essential to work closely with each patient for an individualized treatment plan that is balanced and sustainable,” she said.

Velazquez is a consultant to Novo Nordisk and an advisory board member of Intellihealth, Weight Watchers, and Eli Lilly. Iizuka, Mullally, and Wolver declared no competing interests.

Marilynn Larkin, MA, is an award-winning medical writer and editor whose work has appeared in numerous publications, including Medscape Medical News and its sister publication MDedge, The Lancet (where she was a contributing editor), and Reuters Health.