Effectiveness of slow eating intervention tested in overweight and obese women

Obesity can be prevented by promoting healthy eating habits and reducing the pace of eating. A slow eating rate effectively reduces energy intake by enhancing satiety.

Some techniques that can reduce the eating rate, elevate satiation and reduce short-term energy intake are thorough chewing and enhancing inter-bite intervals. These techniques offer more time for oral processes, prolonged gastrointestinal exposure, and increase the levels of satiety hormones, which in turn, helps decrease the amount of food consumed.

Background

It is extremely important to improve within-meal eating behaviors without changing eating techniques. Several population-based studies have indicated an association between eating rates and body weight. A large-scale Japanese study revealed that eating rate was positively related to body mass index (BMI).

Faster eating rates promote weight gain and insulin resistance, resulting in rapid nutrient absorption and an enhanced risk of fatty liver, visceral fat deposition, and dyslipidemia. In contrast, slow eating improves glucose homeostasis along with other metabolic factors.

Interestingly, twelve months of lab-based eating-rate training resulted in weight loss in obese adolescents. This strategy also improved satiety hormones and HDL cholesterol. However, non-lab-based strategies must be developed for more practical application to modify adult meal-eating behavior that could help weight management.

About the study

A recent Eating Behaviors study has aimed to develop and test the effectiveness of a 5-week slow-eating intervention in obese women. The impact of a modified within-meal eating behavior intervention on meal duration, eating rate, and energy intake was assessed using a parallel group design. 

The eating pace was defined as intake in grams and kcals per minute by obese or overweight women. This study selected women instead of men to maintain sample homogeneity, as it is an extension of previous research.

The current study delivered a 5-week slow-eating intervention through individual counseling or in small groups. In addition, a non-treated control group was formed, which helped scientists evaluate the treatment group's effectiveness. This study hypothesized that women in the slow-eating intervention group would significantly reduce their eating rate compared to the control group. 

All participants were between 18 and 38 years of age and claimed themselves to be fast eaters on a Personal Health History Questionnaire. Participants who were addicted to caffeine or alcohol, smokers, and those who had allergies to study test foods were excluded.

This study did not consider individuals with a history of chronic diseases that affect body weight, those with eating disorders, and pregnant women.

Study findings

The authors provided eating instructions to the participants in five sessions. Some of the instructions included using smaller bites, thorough chewing, swallowing, and pausing between bites. These techniques decreased the eating rates and prolonged meal duration, which in turn increased palatability ratings. Consistent with previous studies, the current study revealed that slower eating decreased energy intake.

The effectiveness of these sessions was assessed based on the changes in eating behavior and energy intake compared to the control group who did not receive any eating-related instructions.

After five weeks of intervention, the experimental group revealed decreased eating rate in women by 22 kcals/minute. As expected, no change was observed in the control group. In addition, longer meal duration was found in the experimental group post-intervention. Importantly, these improvements were observed in those who received one-on-one counseling as well as small-group counseling.

Although improvements in eating behavior were observed in the experimental group, no significant reduction in energy intake was observed post-intervention. Previous studies indicated that longer meal duration leads to higher energy intake. However, in the current study, no increase in energy intake was observed, which could be due to a longer meal duration coupled with a slow eating rate.

Conclusions

The key strength of the current study is the implementation and assessment of three combined slow eating techniques, i.e., small bite size, through chewing, and longer pause to allow complete swallowing.

The current study also has some limitations that include a lack of randomization while forming the experimental and control group. Although a relatively short study duration reduced the possibility of chronological bias, more research is required to validate the findings.

This study re-emphasized that eating pace, which was previously perceived as inherent behavior, could be slowed down in a relatively short duration, irrespective of intervention modality, i.e., one-on-one or group counseling. Based on the five weeks of intervention, the experimental group revealed decreased eating rate of 22 kcals/minute.

In the future, researchers must investigate the effect of modified slow eating techniques and how they affect satiety and energy intake. This research could help determine the specific aspect of the slow eating technique that is resistant to change during interventions.

Written by

Dr. Priyom Bose

Priyom holds a Ph.D. in Plant Biology and Biotechnology from the University of Madras, India. She is an active researcher and an experienced science writer. Priyom has also co-authored several original research articles that have been published in reputed peer-reviewed journals. She is also an avid reader and an amateur photographer.