Research: Weight Management Benefits From Savouring Meals
09 May 2014 --- Researchers at Tokyo Institute of Technology use quantitative studies to identify significant correlations between thoroughly chewing food and the energy expenditure related to food digestion, absorption and storage. The benefits of eating slowly and chewing thoroughly have been proposed for over a century.
Now Yuka Hamada Hideaki Kashima and Naoyuki Hayashi have made quantitative studies of the relation between chewing and physiological parameters subsequent to a meal such as circulation and energy expenditure. As they point out “If chewing alters digestion-induced thermogenesis, its importance should be incorporated into weight management strategies.”
The researchers based at Kyushu University and Tokyo Institute of Technology in Japan monitored 11 healthy normal-weight test subjects given 100 kcal of solid food and 10 given 300 kcal of solid food. Both sets of subjects undertook two trials – one where they swallowed the food as rapidly as possible and one where they chewed as many times as possible.
The energy expenditure associated with digestion, absorption and storage of food, known as diet-induced thermogenesis, was significantly higher when the food was eaten slowly with a high number of chews. Previous research has indicated that increased orosensory stimulation increases this energy expenditure, which may be linked to the effects of leisurely and careful food consumption on diet-induced thermogenesis.

The researchers measured oxygen uptake and body mass to calculate the diet-induced thermogenesis and also monitored blood flow around the digestive organs by measuring artery diameters and blood velocities for 90 minutes after the food was taken. Correlations between different measured parameters suggest that the increased energy expenditure is associated with increases in the blood flow around the digestive organs.
“These findings suggest a partial link between obesity trends and chewing,” they conclude. Further tests are needed to investigate responses to food that more closely resembles a regular meal with higher calorie content and greater variation in the nutritional content.
Reference
Yuka Hamada Hideaki Kashima and Naoyuki Hayashi, The number of chews and meal duration affect diet-induced thermogenesis and splanchnic circulation. Obesity, Volume 22, Issue 5, pages E62–E69, May 2014 (Article first published online: 1 MAY 2014).