Effect of chewing behavior modification on food intake, appetite and satiety-related hormones: A Systematic Review

Purpose: Obesity has become a growing public health issue worldwide. Studies have shown that eating rate is one of the most important factors to consider in the strategies to prevent and/or treat obesity. Eating rate can be reduced through different strategies, such as an increase in oro-sensory exposure, the modification of food texture, and an increase in the number of chewing cycles. The aim of this systematic review was to analyze the available evidence regarding the effect of chewing behavior modification on the parameters that contribute to obesity. Methods: A systematic search was done on the electronic databases Pubmed, Cochrane Central Register of Controlled Trials, and Scopus, using the terms "mastication", "chewing", "chewing speed", "prolonged chewing", "number of chews", "masticatory cycles" "satiety" "satiety response" "appetite", "appetite regulation", "nutritional status" and "obesity". Results: A total of 23 intervention studies were selected that intervened in the participants' chewing behavior, either by reducing the eating rate, increasing oro-sensory exposure, food hardness or the number of chewing cycles. In most studies these interventions were effective at reducing food intake, subjective appetite and improving the plasma levels of satiety-related hormones and metabolites; moreover, they reduced body mass index in the long term. Conclusion: The currently available evidence seems to indicate that modifications to chewing behavior can bring with it a myriad of benefits for the treatment of obesity.

Propósito: La obesidad se ha convertido en un problema de salud pública creciente a nivel mundial. Investigaciones han demostrado que la tasa de ingesta es uno de los factores importantes a considerar en las estrategias para prevenir o tratar la obesidad. La tasa de ingesta puede reducirse a través de diferentes estrategias; el aumento de la exposición oro-sensorial, la modificación de la textura de los alimentos y el aumento en el número de ciclos masticatorios. El objetivo de esta revisión sistemática fue analizar la evidencia disponible sobre el efecto de la modificación de la conducta masticatoria sobre los parámetros que contribuyen a la obesidad. Métodos: Se realizó una búsqueda sistemática en las bases de datos electrónicas Pubmed, Cochrane Central Register of Controlled Trials y Scopus, con los términos "mastication", "chewing", "chewing speed", "prolonged chewing", "number of chews", "masticatory cycles" "satiety" "satiety response" "appetite", "appetite regulation", "nutritional status" y "obesity". Resultados: Se seleccionaron 23 estudios que intervenían en el comportamiento masticatorio de los participantes, ya sea reduciendo de la tasa de ingesta, aumentando la exposición oro-sensorial, dureza de los alimentos y número de ciclos masticatorios. Estas intervenciones resultaron ser efectivas para reducir la ingesta de alimentos, el apetito subjetivo y mejorar los niveles plasmáticos de las hormonas y metabolitos relacionados con la saciedad, además, a largo plazo, permitieron reducciones en el índice de masa corporal. Conclusión: La evidencia disponible actualmente parece señalar que las modificaciones en el comportamiento masticatorio pueden traer consigo múltiples beneficios para el tratamiento de la obesidad.

Influence of the Size of the Spoon on the Eating rate, Energy Intake and the Satiety Levels of Female College Students / 대한지역사회영양학회지

OBJECTIVES: This study examined the influence of different sizes of spoons (normal spoon, 8.3 cc vs small spoon, 4 cc) on eating rate, energy intake and the satiety levels of female college students. METHODS: Twenty four healthy female college students participated in this study once a week for 2 weeks. Two hundred ten grams of cooked rice and 250 g of beef shank soup with a normal spoon and same amount of rice and soup with a small size spoon were served to the same participants over two consecutive weeks. After each lunch, the eating rate, energy intake, and the satiety levels were measured. RESULTS: Results showed that the subjects who were using a small spoon ate less beef shank soup (149.0 kcal) (p < 0.01) and had lower total energy intake (423.3 kcal) (p < 0.05) than using a normal spoon (178.7 and 461.1 kcal, respectively). Also, the meal time (15.7 min) (p < 0.01), a serving per one spoon (8.6 g) (p < 0.001), and eating rate (27.9 g/min) (p < 0.001) of those who used a small spoon were significantly different than that of those who used a normal spoon (13.6 min, 12.5 g and 35.7 g/min, respectively). However, despite consuming less energy at lunch, the level of satiety after eating from the small spoon was not significantly different from the normal spoon immediately after, 1 hour after and 2 hour after lunch. CONCLUSIONS: Our results revealed that students were able to control their eating rate by using a small spoon and they could feel full enough even though they eat less. In conclusion, eating rate decrease by using a small spoon may play an important role in food intake.

The Relationships of Chewing Frequency, Eating Rates, and Food Consumption with the Body Mass Index and Gender of College Students

In this study, we examined chewing frequency, eating rates, and food consumption volume according to the body mass index of male and female college students. Twenty-five male college students were divided into a normal weight male group ( or =23 body mass index, n=11). Twenty-five female college students were divided into a normal weight female group ( or =23 body mass index, n=4). Subjects were provided with abundant fried rice and allowed to consume it at their own pace. Chewing frequency, total mealtime, rate of eating, consumption volume, calorie intake, and the amount of one bite were measured. There were no significant differences in chewing frequency, total mealtime, rate of eating, consumption volume, calorie intake, and the amount of one bite between the normal and obese male groups. There were also no significant differences in chewing frequency, consumption volume, calorie intake, and the amount of one bite between the normal and obese female groups. However, the obese female group had a significantly shorter mealtime and significantly higher eating rate compared with the normal group. Thus, our study suggests that females who eat a meal for a longer time may reduce their food intake, consequently inducing body weight loss.

The Relationship between Food Intake, Sodium Intake and Satiety Rate and the Methods of Consuming Soup

In this study, we examined food intake, sodium intake, and satiety rate for different methods of consuming soup. Healthy young women (n=50) participated in this study. The subjects ate cooked rice and soup using a method that they preferred and then they were assigned into separate intake groups based on how they consumed their rice and soup. One group consisted of women that ate their soup and cooked rice separately (separate intake group, n=30). The second group consisted of the women who mixed the rice and the soup prior to consumption (mixed intake group, n=20). The mixed intake group consumed significantly more food (p<0.001) and sodium (p<0.05) than the separate intake group. Because of the high water content and ease of swallowing for the mixed intake method, the eating rate of the mixed intake group (42.5 g/min) was significantly higher than that of the separate intake group (28.8 g/min) (p<0.01). However, despite consuming 79.5 g more food at lunch, the rates of satiety were not significantly different before and after eating between the mixed intake and separate intake group. Therefore, eating rate, consumption norms and concept of "clean one's bowl" may influence food intake and sodium intake. Although more studies are needed, these data suggest eating cooked rice and soup separately may help to control obesity and hypertension.