Eating fast leads to obesity: findings based on self-administered questionnaires among middle-aged Japanese men and women

Greater Numbers of Chews and Bites and Slow External Rhythmic Stimulation Prolong Meal Duration in Healthy Subjects

BACKGROUND/AIM

Slow eating is recommended for obese individuals. We aimed to determine the associations between meal duration and various factors (sex, numbers of chews and bites, eating tempo (including forced rhythm with a metronome) and BMI).

METHODS

Using a test meal (a quarter slice of pizza), we tested the sex difference of the meal duration, numbers of chews and bites, and eating tempo for thirty three healthy subjects (M: 15; F: 18) aged 37.2 ± 11.1 years via unpaired t tests. Next, factors influencing meal duration were identified via multivariate analysis (adjusted for sex), with meal duration as the dependent variable.

RESULTS

The meal duration and numbers of chews and bites differed significantly between sexes (63.1 ± 20.7 vs. 87.4 ± 22.8, p = 0.003; 80.3 ± 28.7 vs. 107.0 ± 36.1, p = 0.02; 2.1 ± 1.1 vs. 4.5 ± 2.6, p = 0.001, respectively), but the chewing tempo was similar (p = 0.32). Meal duration was associated with the number of chews (β = 0.6 [0.4, 0.7], p < 0.001) and bites (5.8 [2.5, 9.2], p = 0.001) but not with BMI (p = 0.52) or chewing tempo (p = 0.99). Finally, when a metronome was used to force rhythmic stimulation (0/40/80/160 bpm), compared with 0 bpm, slow stimulation (40 bpm) resulted in increased meal duration (mean difference [95% CI] = -47.0 [-66.4, -27.7], p < 0.0001), chews (-28.6 [-44.5, 12.8], p = 0.0003), and bites (-4.9 [-7.9, 1.9] p = 0.001) and delayed tempo (10.4 [4.5, 16.3], p = 0.0004).

CONCLUSIONS

Meal duration was positively associated with the numbers of chews and bites and negatively associated with chewing tempo. Thus, increasing the numbers of bites and chews and slowing the eating tempo may prolong meal duration.

Simultaneous Speech and Eating Behavior Recognition Using Data Augmentation and Two-Stage Fine-Tuning

Speaking and eating are essential components of health management. To enable the daily monitoring of these behaviors, systems capable of simultaneously recognizing speech and eating behaviors are required. However, due to the distinct acoustic and contextual characteristics of these two domains, achieving high-precision integrated recognition remains underexplored. In this study, we propose a method that combines data augmentation through synthetic data creation with a two-stage fine-tuning approach tailored to the complexity of domain adaptation. By concatenating speech and eating sounds of varying lengths and sequences, we generated training data that mimic real-world environments where speech and eating behaviors co-exist. Additionally, efficient model adaptation was achieved through two-stage fine-tuning of the self-supervised learning model. The experimental evaluations demonstrate that the proposed method maintains speech recognition accuracy while achieving high detection performance for eating behaviors, with an F1 score of 0.918 for chewing detection and 0.926 for swallowing detection. These results underscore the potential of using voice recognition technology for daily health monitoring.

Circadian Deregulation: Back Facing the Sun Toward Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) Development

Earth's rotation around its axis has pressured its inhabitants to adapt to 24 h cycles of day and night. Humans adapted their own circadian rhythms to the Earth's rhythms with a light-aligned awake-sleep cycle. As a consequence, metabolism undergoes drastic changes throughout the circadian cycle and needs plasticity to cope with opposing conditions in the day (when there is an increase in energy demands and food availability), and during the night (when prolonged fasting couples with cyclic changes in the energy demands across the sleep stages). In the last century, human behavior changed dramatically with a disregard for the natural circadian cycles. This misalignment in sleep and eating schedules strongly modulates the metabolism and energy homeostasis, favoring the development of obesity, metabolic syndrome, and metabolic dysfunction-associated steatotic liver disease (MASLD). This review summarizes the effects of circadian disruption, with a particular focus on the feeding and sleep cycles in the development of MASLD and hepatocellular carcinoma.

Mastication and oral myofunctional status in excess weight children and adolescents: A cross-sectional observational study

BACKGROUND

Masticatory function seems to play a role in the aetiology of obesity. However, literature on the association between oral myofunctional status and overweight and obesity in children and adolescents is scarce and contrasting.

OBJECTIVE

To compare masticatory performance, orofacial myofunctional status and tongue strength and endurance between children and adolescents with overweight and obesity and those with normal weight.

METHODS

Thirty children and adolescents with overweight and obesity and 30 subjects with normal weight matched for age and sex were recruited. All subjects were evaluated with the Test of Masticating and Swallowing Solids in Children (TOMASS-C) for masticatory performance and with the Italian Orofacial Myofunctional Evaluation with Scores (I-OMES) for the orofacial myofunctional status. Anterior and posterior maximum tongue pressures and tongue endurance were measured. Parents-reported (PRO) duration of meals was recorded. Data were compared between the groups through the paired samples t-test or the Wilcoxon signed-rank test.

RESULTS

Children and adolescents with overweight showed significantly lower number of bites (p = .033), lower I-OMES scores (p < .05), and shorter meal duration (p = .005) compared to their peers with normal weight. No significant differences were found between the two groups for the number of swallows, the number of masticatory cycles and the total time of the TOMASS-C, and none of the tongue pressure measurements.

CONCLUSIONS

Eating in children and adolescents with overweight and obesity is characterised by a larger bolus sizes and shorter PRO meal duration. Additionally, overweight and obesity seem to be associated with poorer orofacial skills and structures in the paediatric population.

Twin Study: The Factors Affecting the Serum LDL-C and HDL-C Levels and an RNA-Seq Analysis in Mononuclear Cells in Monozygotic Twins

AIM

A twin study is a valuable tool for elucidating the acquired factors against lifestyle diseases such as dyslipidemia, diabetes mellitus, and obesity. We aimed 1. to investigate the factors that affect low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) in monozygotic (MZ) twins, and 2. to identify genes which expression levels changed in pairs with large differences in LDL-C or HDL-C levels.

METHODS

The registered database at the Center for Twin Research, Osaka University, containing 263 pairs of MZ twins, was analyzed. 1. The effects of smoking, exercise, nutritional factors, and anthropometric and biochemical parameters on LDL-C or HDL-C levels were examined in MZ twins. 2. RNA sequencing in the peripheral blood mononuclear cells of 59 pairs was analyzed for large differences of LDL-C or HDL-C groups.

RESULTS

1. The ΔLDL-C levels were significantly associated with an older age, the ΔTG levels, and ΔBMI. ΔHDL-C levels were associated with the ΔBMI, ΔTG, ΔTP, and ΔLDL-C levels. The HDL-C levels were affected by smoking and exercise habits. The intakes of cholesterol and saturated fatty acids were not associated with the LDL-C or HDL-C levels. 2. An RNA sequencing analysis revealed that the expression of genes related to the TLR4 and IFNG pathways was suppressed in accordance with the HDL-C levels in the larger ΔHDL-C group among the 59 pairs.

CONCLUSION

We identified the factors affecting the LDL-C or HDL-C levels in monozygotic twins. In addition, some types of inflammatory gene expression in peripheral blood mononuclear cells were suppressed in accordance with the HDL-C levels, thus suggesting the importance of weight management and exercise habits in addition to dietary instructions to control the LDL-C or HDL-C levels.

Practice Recommendations for Metabolic Dysfunction-Associated Steatotic Liver Disease by the Indian Society of Pediatric Gastroenterology, Hepatology and Nutrition (ISPGHAN)

JUSTIFICATION

There has been an alarming increase in metabolic dysfunction-associated steatotic liver disease (MASLD) and it is now the most common chronic liver disease worldwide, in both adult and pediatric populations. The lack of regional guidelines has hampered the formulation of national policies for prevention and management of MASLD in children. Therefore, we formulated recommendations for steatotic liver disease in children.

OBJECTIVES

To review the existing literature on the burden and epidemiology of pediatric MASLD and formulate recommendations for diagnostic evaluation, prevention, and management strategies.

PROCESS

The Indian Society of Pediatric Gastroenterology, Hepatology, and Nutrition invited national and international stakeholders to participate in a consensus meeting held on April 20, 2024, in Mumbai, Maharashtra, India. Various aspects of pediatric steatotic liver disease were deliberated upon and a consensus document and recommendations were formulated after several rounds of discussion.

RECOMMENDATIONS

Metabolic dysfunction-associated steatotic liver disease (MASLD) should be used as the preferred term in place of non-alcoholic fatty liver disease (NAFLD). There is a high prevalence of steatotic liver disease (SLD) among Indian children and adolescents, especially those who are overweight or obese. This condition may be progressive in childhood and associated with increased morbidity and mortality in adulthood. Various lifestyle, dietary, and genetic factors may predispose individuals to MASLD, including an increased intake of calorie-dense processed foods, sweetened sugar beverages, excessive screen time, higher sedentary time and lack of moderate to vigorous physical activity. MASLD is usually asymptomatic or presents with mild, non-specific symptoms and therefore, a high degree of suspicion is required for early diagnosis. MASLD is usually associated with cardiometabolic factors (hypertension, insulin resistance/diabetes mellitus, and/or dyslipidemia) and secondary causes should be excluded in all cases, particularly in the presence of red flag signs. Screening for MASLD should be considered in all obese children (body mass index or BMI ≥95th percentile) and in all overweight children (BMI ≥ 85th and <95thpercentile) with additional risk factors, such as prediabetes/diabetes, dyslipidemia, positive family history of metabolic syndrome, obstructive sleep apnea, and hypopituitarism. Abdominal ultrasound in combination with alanine aminotransferase (ALT) levels should be used as a screening test for MASLD in Indian children as per the proposed algorithm. Diet (any hypocaloric diet) and exercise (aerobic, resistance, or a combination of both; moderate to high intensity; regular in frequency) remain the cornerstones of pediatric MASLD management. Pharmacotherapy and/or endoscopic/surgical techniques for obesity should be considered as adjuncts and should be considered only after a failed adequate trial of lifestyle modifications.

Rule-based systems to automatically count bites from meal videos

Eating behavior is a key factor for nutritional intake and plays a significant role in the development of eating disorders and obesity. The standard methods to detect eating behavior events (i.e., bites and chews) from video recordings rely on manual annotation, which lacks objective assessment and standardization. Yet, video recordings of eating episodes provide a non-invasive and scalable source for automation. Here, we present a rule-based system to count bites automatically from video recordings with 468 3D facial key points. We tested the performance against manual annotation in 164 videos from 15 participants. The system can count bites with 79% accuracy when annotation is available, and 71.4% when annotation is unavailable. The system showed consistent performance across varying food textures. Eating behavior researchers can use this automated and objective system to replace manual bite count annotation, provided the system's error is acceptable for the purpose of their study. Utilizing our approach enables real-time bite counting, thereby promoting interventions for healthy eating behaviors. Future studies in this area should explore rule-based systems and machine learning methods with 3D facial key points to extend the automated analysis to other eating events while providing accuracy, interpretability, generalizability, and low computational requirements.

The timing of energy intake

The aim of the paper is to review the current evidence on the impact of 'the timing of energy intake' on the risk of developing obesity and obesity-related metabolic diseases. The prevalence of obesity is currently increasing worldwide thus becoming a severe health burden for most countries. Indeed, obesity represents a risk factor for several non-communicable diseases such as cancer, type 2 diabetes, dyslipidaemia, CVD and overall mortality. In order to treat obesity, several pharmacological approaches have been developed and are indicated for subjects with obesity with a BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 and obesity-related comorbidities. For severe obesity (BMI ≥ 40 kg/m2), bariatric surgery represents a promising approach. The most common bariatric surgical procedures are represented by the Roux-en-Y gastric bypass, laparoscopic adjustable band, laparoscopic gastric sleeve and biliopancreatic diversion with duodenal switch. Both anti-obesity pharmacological and surgical treatments require change in lifestyle. When a nutritional plan is established, attention is usually paid to macronutrient composition and energy intake, while 'the time of food' is not taken into account. Chronotype, which is the attitude of a subject to carry out most of their daily activities in the first (morning chronotype) or second half (evening chronotype) of the day, has been reported to have a role in the pathogenesis of obesity and obesity-related cardiometabolic diseases as well as eating speed. Thus, adopting a physiological timing of energy intake could be an additional strategy to potentiate the current anti-obesity approaches.

Association of health behaviors, dietary habits, and oral health with weight gain after 20 years of age in community-dwelling Japanese individuals aged 40 years and older: a cross-sectional study

OBJECTIVES

This cross-sectional study investigated the factors associated with weight gain ≥ 10 kg after 20 years of age in the general Japanese population, with a focus on the number of teeth.

MATERIALS AND METHODS

We included individuals aged ≥ 40 years from Yamagata prefecture, Japan from 2017-2021. A postal survey was conducted using a self-administered questionnaire; 5,940 participants were included in the final analysis. The questionnaire included items on lifestyle factors, medical history, physical and mental conditions, oral health, and dietary intake. A multivariate logistic regression analysis was used to identify independent associations between weight gain ≥ 10 kg after 20 years of age and various parameters; adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated.

RESULTS

Less than 20 teeth, male sex, drinking habit frequency, eating very fast or fast, and a higher frequency of eating-away-from-home were significant factors associated with weight gain ≥ 10 kg after 20 years of age; individuals with < 20 versus > 20 teeth exhibited a 1.35-fold higher OR (95% CI 1.15-1.59; p < 0.01).

CONCLUSIONS

Our results suggest that having < 20 teeth may affect weight gain ≥ 10 kg after 20 years of age. However, owing to the cross-sectional study design, causality could not be determined. Therefore, maintaining healthy lifestyle behaviors to avoid tooth loss may also affect weight gain ≥ 10 kg after 20 years of age.

CLINICAL RELEVANCE

Having < 20 teeth has the potential to affect long-term weight gain after 20 years of age.

[Association between subjective chewing conditions and dietary habits in Japanese workers]

OBJECTIVES

Previous studies on the elderly have reported that they avoid fiber-rich and hard foods in favor of softer foods as chewing ability declines. However, evidence of worker chewing conditions and dietary habits is scarce. This study aimed to clarify the association between chewing conditions and dietary habits in workers.

METHODS

The subjects included 6,703 workers (45.6 ± 10.2 years, range 18-64 years) who underwent medical and dental check-ups from April 2018 to March 2019 with no missing data. We classified workers into two groups, those with good chewing conditions (GCC) and those with poor chewing conditions (PCC) according to their responses to the chewing condition item in our questionnaire. We performed logistic regression analysis using the questionnaire dietary habits item response as the objective variable and chewing conditions as the explanatory variable and adjusting for sex, age, number of present teeth, periodontal pocket depth, oral hygiene status, Body Mass Index, smoking habits, alcohol intake, exercise habits, history of present illness, and stages of transtheoretical model. Additionally, we performed subgroup analysis using a similar framework stratified by sex and age groups (under 40 or older).

RESULTS

We found significant negative associations with PCC for the following dietary habits (p < .05): Awareness of balanced diet; Regular consumption of dark green and deep yellow vegetables; Eating slowly and chewing well; Frequent consumption of seaweed and small fish; Having three meals at almost at the same time every day; Having breakfast almost every day; Eating protein dishes with every meal; Frequently consuming dairy products; Finishing eating at least two hours before bedtime. Furthermore, we found significant positive associations with PCC for the following items (p < .05): Having on average two or more bottles/cans of juice or coffee a day; Frequently eating heavy meat dishes; Frequently eating deep-fried foods such as fried dishes and pork cutlets; Frequently having instant or processed foods; Eating two or more kinds of Western or Japanese confectioneries or snacks on average a day; Frequently eating salty food; Regularly having snacks or late-night meals. Additionally, similar trends were also observed following subgroup analysis, regardless of sex or age.

CONCLUSIONS

This study suggests that workers with PCC may retain undesirable dietary habits, regardless of sex and age. Therefore, it is necessary to expand dental check-ups in the workplace and to promote dental health guidance that targets all workers.

Relationships of rapid eating with visceral and subcutaneous fat mass and plasma adiponectin concentration

Rapid eating has been demonstrated to be associated with obesity and overweight. However, few studies have characterized the separate relationships of eating speed with visceral and subcutaneous fat mass or circulating adiponectin concentration. We hypothesized that rapid eating is associated with the larger visceral fat tissue (VFT) area and lower adiponectin concentration, but not with the subcutaneous fat tissue (SFT) area in men and women. We performed a cross-sectional study of 712 adults aged 20-86 years (528 men and 184 women; mean ± SD age 59.36 ± 13.61 years). The participants completed a self-reported questionnaire, and underwent anthropometric and laboratory measurements and computed tomographic imaging of the abdomen as a part of annual medical check-ups. Multivariate linear regression analyses revealed that rapid eating was associated with larger visceral (B = 24.74; 95% CI 8.87-40.61, p = 0.002) and subcutaneous fat areas (B = 31.31; 95% CI 12.23-50.38, p = 0.001), lower adiponectin concentration (B =  - 2.92; 95% CI - 4.39- - 1.46, p < 0.001), higher body mass index (BMI) (B = 2.13; 95% CI 1.02-3.25, p < 0.001), and larger waist circumference (B = 5.23; 95% CI 2.16-8.30, p < 0.001) in men, which is partially consistent with the hypothesis. In contrast, rapid eating was found to be associated only with BMI, and not with abdominal adipose area or adiponectin concentration in women, which is a result that is not consistent with the hypothesis. These results suggest that there is no difference in the association of rapid eating with VFT and SFT areas.

Effect of mastication evaluation and intervention on body composition and biochemical indices in female patients with obesity: a randomized controlled trial

BACKGROUND

A limited number of studies have evaluated the masticatory indices of individuals with obesity who only chew their food a few times and for shorter duration or who were provided with an instructional intervention. This study aimed to examine the effects of a 6-month instructional mastication intervention on the body composition and biochemical indices in female patients with obesity.

METHODS

Female patients with obesity were randomly classified into a conventional treatment group (CTG; 12 individuals), which only received normal nutritional and exercise guidance, and a mastication intervention group (MIG; 16 individuals), which received an additional mastication guidance. The MIG received guidance on foods requiring increased number of chews and chewing duration, eating techniques, and the proper method of cutting foods.

RESULTS

Changes in the masticatory, body composition, and biochemical indices were compared before and after the 6-month intervention. The values of body composition indices decreased significantly in both groups; however, the rate of change in body mass index significantly decreased in the MIG. In addition, the values of biochemical indices were significantly decreased in the MIG compared with that in the CTG, which is attributed to the addition of mastication instruction to female patients with obesity.

CONCLUSION

Increasing the number of chews and duration of chewing times for carbohydrates, which are staple foods, possibly contributed to weight loss and improvement of glucose metabolism.

TRIAL REGISTRATION

UMIN, UMIN000025875. Registered on 27 Jan 2017.

Effect of Obesity on Masticatory Muscle Activity and Rhythmic Jaw Movements Evoked by Electrical Stimulation of Different Cortical Masticatory Areas

This study investigates rhythmic jaw movement (RJM) patterns and masticatory muscle activities during electrical stimulation in two cortical masticatory areas in obese male Zucker rats (OZRs), compared to their counterparts-lean male Zucker rats (LZRs) (seven each). At the age of 10 weeks, electromyographic (EMG) activity of the right anterior digastric muscle (RAD) and masseter muscles, and RJMs were recorded during repetitive intracortical micro-stimulation in the left anterior and posterior parts of the cortical masticatory area (A-area and P-area, respectively). Only P-area-elicited RJMs, which showed a more lateral shift and slower jaw-opening pattern than A-area-elicited RJMs, were affected by obesity. During P-area stimulation, the jaw-opening duration was significantly shorter (p < 0.01) in OZRs (24.3 ms) than LZRs (27.9 ms), the jaw-opening speed was significantly faster (p < 0.05) in OZRs (67.5 mm/s) than LZRs (50.8 mm/s), and the RAD EMG duration was significantly shorter (p < 0.01) in OZRs (5.2 ms) than LZR (6.9 ms). The two groups had no significant difference in the EMG peak-to-peak amplitude and EMG frequency parameters. This study shows that obesity affects the coordinated movement of masticatory components during cortical stimulation. While other factors may be involved, functional change in digastric muscle is partly involved in the mechanism.

Physical, Psychiatric, and Social Comorbidities of Individuals with Schizophrenia Living in the Community in Japan

The physical, psychiatric, and social comorbidities interfere with the everyday activities of community-dwelling individuals with schizophrenia and increase the risk of their readmission. However, these comorbidities have not been investigated comprehensively in Japan. We conducted a self-reported internet survey in February 2022 to identify individuals aged 20-75 years with and without schizophrenia using a prevalence case-control study. The survey compared physical comorbidities such as being overweight, hypertension, and diabetes; psychiatric comorbidities such as depressive symptoms and sleep disturbances; social comorbidities such as employment status, household income, and social support between participants with and without schizophrenia. A total of 223 participants with schizophrenia and 1776 participants without schizophrenia were identified. Participants with schizophrenia were more likely to be overweight and had a higher prevalence of hypertension, diabetes, and dyslipidemia than participants without schizophrenia. Additionally, depressive symptoms, unemployment, and non-regular employment were more prevalent in participants with schizophrenia than those without schizophrenia. These results highlight the necessity of comprehensive support and interventions addressing physical, psychiatric, and social comorbidities in individuals with schizophrenia in the community. In conclusion, effective interventions for managing comorbidities in individuals with schizophrenia are necessary to enable them to continue to live in the community.

Association between dietary habits and incident thyroid cancer: A prospective cohort study

Background

In addition to the thyroid cancer (TC) risk from lifestyle and environmental factors such as radiation exposure, some studies have indicated that diet may affect TC development; however, previous findings are inconsistent. The objective of our study was to investigate the association between dietary habits and TC risk in a Korean population.

Materials and methods

A total of 13,973 participants were selected after excluding ineligible subjects from the Cancer Screenee Cohort at National Cancer Center in Korea from October 2007 to December 2021. Participants were followed until May 2022 to identify incident TC cases. Information on dietary habits and general characteristics was collected using a self-report questionnaire administered at enrollment without keeping track of changes in eating habits during the follow-up period. A Cox proportional hazards model was used to determine the hazard ratio (HR) and 95% confidence interval (CI) of TC risk for each dietary factor.

Results

A total of 138 incident TC cases were identified during the median follow-up period of 7.6 years. Of the 12 dietary habits evaluated, only two habits showed significant associations with TC. A significantly decreased TC risk was found among participants who consumed milk and/or dairy products 5 or more days a week [adjusted HR (aHR), 0.58; 95% CI, 0.39-0.85]. Notably, a stronger protective effect of dairy consumption was observed in participants aged ≥ 50 years (aHR, 0.44; 95% CI, 0.26-0.75), in women (aHR, 0.53; 95% CI, 0.35-0.81), and in non-smokers (aHR, 0.60; 95% CI, 0.39-0.92). There was a reduced risk of TC in participants with meal durations longer than 10 min (aHR, 0.58; 95% CI, 0.41-0.83). However, this association was limited to individuals aged ≥ 50 years (aHR, 0.49; 95% CI, 0.31-0.79), women (aHR, 0.61; 95% CI, 0.41-0.90), and non-smokers (aHR, 0.62; 95% CI, 0.41-0.92).

Conclusion

Our findings suggest that consuming milk and/or dairy products 5 or more days a week and having a meal duration longer than 10 min could be protective factors against TC, especially in individuals aged ≥ 50 years, women and non-smokers. Further prospective studies are needed to investigate the association of dietary intake with specific types of TC.

Eating pace instruction is effective in slowing eating rate in women with overweight and obesity

Slow eating is associated with lower body mass index (BMI), enhanced satiety, and reduced food intake in laboratory settings. This study developed and tested a 5-week slow-eating intervention, delivered either through individual or small group weekly meetings, in women with overweight and obesity. Women (n = 65; 20.5 ± 3.6 years; BMI 31.3 ± 2.7 kg/m²) were assigned to experimental or parallel non-treatment control. Main outcomes, measured pre- and post-intervention, included eating rate, meal duration, and energy intake during a standardized meal served on a universal eating monitor. Exploratory outcomes included Weight Related Eating Questionnaire (WREQ), Intuitive Eating Scale (IES), and Mindful Eating Questionnaire (MEQ) scores. All women in the experimental group underwent the same slow-eating intervention, but half had individual sessions while the other half had small group sessions. No differences were seen for any outcomes between session modalities, so experimental data were pooled (n = 25) and compared to control data (n = 25). Time-by-group interactions showed reduced eating rate (F_(1,48df) = 13.04, η² = 0.214, p = .001) and increased meal duration (F_(1,48df) = 7.949, η² = 0.142, p = .007) in the experimental group compared to the control group but change in energy intake was not significant (F_(1,48df) = 3.298, η² = 0.064, p = .076). Experimental within-group changes for WREQ subscale scores External Cues (t₍₂₃₎ = 3.779, p = .001) and Emotional Eating (t₍₂₃₎ = 2.282, p = .032) decreased over time, along with increased total and summary IES (t₍₂₃₎ = 2.6330, p = .015) and MEQ (t₍₂₃₎ = 2.663, p = .014) scores. Promising findings of reduced eating rate, increased meal duration, and improved WREQ, IES, and MEQ scores should be followed up in larger more diverse samples for longer durations.

Development of a Video-Based Tool for the Self-Assessment of Eating Rates in Young Adult Females

Eating speed assessments are often based on self-reports, and establishing objective "ratings" is required to improve accuracy. However, no relevant simple assessment tool incorporating "ratings" is currently available. This study aimed to develop a group-adaptable eating rate assessment tool for young females using smartphones. Fifty female college students were directly observed while eating, and a self-assessment tool for the eating rate was created using video. Using the directly observed eating rate of a test food A as the gold standard (GS), we compared the eating rate self-assessment findings between those obtained using a conventional questionnaire and those obtained using an assessment tool. The validity and reproducibility of the assessment tool were verified. In terms of validity, the correlation coefficient for the GS questionnaire (r=0.442, p<0.001) was similar to that for the self-assessment tool (r=0.491, p<0.001). The reproducibility of repeated measurements of the self-assessment tool was inferior to that of the questionnaire (weighted kappa coefficients; 0.393 vs. 0.804). This may be explained in part by participants selecting the same items with specific words such as "fast" or "slow" on two occasions. As for the validity of test food A, additional measurements for test food C on a subset of subjects (n=16) showed a strong positive correlation (r=0.845, p<0.001) between A and C. The present study suggests that a video-based self-assessment tool we developed for young adult females is straightforward, and allows the subjects to observe specific and visual ratings in a manner that is less burdensome and time-effective than conventional questionnaire methods.

Capturing Eating Behavior from Video Analysis: A Systematic Review

Current methods to detect eating behavior events (i.e., bites, chews, and swallows) lack objective measurements, standard procedures, and automation. The video recordings of eating episodes provide a non-invasive and scalable source for automation. Here, we reviewed the current methods to automatically detect eating behavior events from video recordings. According to PRISMA guidelines, publications from 2010-2021 in PubMed, Scopus, ScienceDirect, and Google Scholar were screened through title and abstract, leading to the identification of 277 publications. We screened the full text of 52 publications and included 13 for analysis. We classified the methods in five distinct categories based on their similarities and analyzed their accuracy. Facial landmarks can count bites, chews, and food liking automatically (accuracy: 90%, 60%, 25%). Deep neural networks can detect bites and gesture intake (accuracy: 91%, 86%). The active appearance model can detect chewing (accuracy: 93%), and optical flow can count chews (accuracy: 88%). Video fluoroscopy can track swallows but is currently not suitable beyond clinical settings. The optimal method for automated counts of bites and chews is facial landmarks, although further improvements are required. Future methods should accurately predict bites, chews, and swallows using inexpensive hardware and limited computational capacity. Automatic eating behavior analysis will allow the study of eating behavior and real-time interventions to promote healthy eating behaviors.

Observational Study on Unhealthy Eating Behavior and the Effect of Sodium-Glucose Cotransporter 2 Inhibitors: The Luseogliflozin Ehime Diabetes Study

INTRODUCTION

Luseogliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor. Unhealthy eating behavior is associated with diabetes, hypertension, and obesity. However, evidence regarding the effect of medications, including SGLT2 inhibitors, on unhealthy eating behavior is limited. This study investigated the association between unhealthy eating behavior and the laboratory and physical findings of Japanese patients with type 2 diabetes given luseogliflozin once daily for 24 weeks.

METHODS

Twenty-nine patients with type 2 diabetes mellitus were enrolled in a 24-week prospective, open-label, single-arm pilot study. The information regarding unhealthy eating behaviors (eating fast, late dinner, nighttime snack, skipping breakfast, and eating until full) was obtained using self-reported questionnaires.

RESULTS

The baseline rate of eating fast, late dinner, nighttime snack, skipping breakfast, and eating until full was 51.7%, 24.1%, 24.1%, 10.3% and 55.2%, respectively. After administration of luseogliflozin, fasting plasma glucose, HbA1c, aspartate aminotransferase (ALT), weight, body mass index, and waist measurement all decreased significantly. High-density lipoprotein cholesterol and hematocrit increased significantly. In the healthy eating behavior group, the improvements of fasting plasma glucose and ALT, but not other variables, were attenuated. HbA1c level was significantly improved in patients with eating fast, while other unhealthy eating behaviors attenuated the effect of luseogliflozin for HbA1c. The effect of leseogliflozin on the relationship between eating behavior and weight reduction was inconsistent after administration luseogliflozin.

CONCLUSION

Luseogliflozin might be more effective for controlling plasma glucose in patients with type 2 diabetes who have a tendency to eat fast, but it might have less effect on those with other unhealthy eating habits.

Impact of Masticatory Behaviors Measured With Wearable Device on Metabolic Syndrome: Cross-sectional Study

Background

It has been widely recognized that mastication behaviors are related to the health of the whole body and to lifestyle-related diseases. However, many studies were based on subjective questionnaires or were limited to small-scale research in the laboratory due to the lack of a device for measuring mastication behaviors during the daily meal objectively. Recently, a small wearable masticatory counter device, called bitescan (Sharp Co), for measuring masticatory behavior was developed. This wearable device is designed to assess objective masticatory behavior by being worn on the ear in daily life.

Objective

This study aimed to investigate the relation between mastication behaviors in the laboratory and in daily meals and to clarify the difference in mastication behaviors between those with metabolic syndrome (MetS) and those without (non-MetS) measured using a wearable device.

Methods

A total of 99 healthy volunteers (50 men and 49 women, mean age 36.4 [SD 11.7] years) participated in this study. The mastication behaviors (ie, number of chews and bites, number of chews per bite, and chewing rate) were measured using a wearable ear-hung device. Mastication behaviors while eating a rice ball (100 g) in the laboratory and during usual meals for an entire day were monitored, and the daily energy intake was calculated. Participants’ abdominal circumference, fasting glucose concentration, blood pressure, and serum lipids were also measured. Mastication behaviors in the laboratory and during meals for 1 entire day were compared. The participants were divided into 2 groups using the Japanese criteria for MetS (positive/negative for MetS or each MetS component), and mastication behaviors were compared.

Results

Mastication behaviors in the laboratory and during daily meals were significantly correlated (number of chews r=0.36; P<.001; number of bites r=0.49; P<.001; number of chews per bite r=0.33; P=.001; and chewing rate r=0.51; P<.001). Although a positive correlation was observed between the number of chews during the 1-day meals and energy intake (r=0.26, P=.009), the number of chews per calorie ingested was negatively correlated with energy intake (r=–0.32, P=.002). Of the 99 participants, 8 fit the criteria for MetS and 14 for pre-MetS. The number of chews and bites for a rice ball in the pre-MetS(+) group was significantly lower than the pre-MetS(–) group (P=.02 and P=.04, respectively). Additionally, scores for the positive abdominal circumference and hypertension subgroups were also less than the counterpart groups (P=.004 and P=.01 for chews, P=.006 and P=.02 for bites, respectively). The number of chews and bites for an entire day in the hypertension subgroup were significantly lower than in the other groups (P=.02 and P=.006). Furthermore, the positive abdominal circumference and hypertension subgroups showed lower numbers of chews per calorie ingested for 1-day meals (P=.03 and P=.02, respectively).

Conclusions

These results suggest a relationship between masticatory behaviors in the laboratory and those during daily meals and that masticatory behaviors are associated with MetS and MetS components.

Trial Registration

University Hospital Medical Information Network Clinical Trials Registry R000034453; https://tinyurl.com/mwzrhrua

Relationship between body mass index and masticatory factors evaluated with a wearable device

Numerous studies have evaluated the relationship between eating behavior and obesity, however few studies have objectively assessed eating behavior. Additionally, the association of masticatory behaviors with masticatory performance remains unclear. This study aimed to verify the relationship between masticatory performance and behavior measured by a wearable masticatory counter, and BMI. 365 healthy adults participated. Mastication behaviors, i.e. number of chews and bites, chewing rate, and chewing time, were measured using wearable masticatory counter while consuming one rice ball (100 g). Masticatory performance was evaluated using testing gummy jelly. Lifestyle habits including exercise, walking, and breakfast, were surveyed by questionnaire. The correlation coefficients between masticatory behaviors and performance and BMI were analyzed. Furthermore, multiple regression analysis was performed. The number of chews showed positive correlation with chewing rate, number of bites and chewing time, but no correlation with masticatory performance. BMI had weak but significant negative correlation with number of chews, bites, chewing time, and masticatory performance, but had no correlation with chewing rate. Multiple regression analysis revealed that BMI was associated with sex, age, number of chews, bites, masticatory performance, and walking speed. In conclusion, masticatory behavior and performance were not interrelated, but both were independently associated with BMI weakly.

Chewing increases postprandial diet-induced thermogenesis

Slow eating, which involves chewing food slowly and thoroughly, is an effective strategy for controlling appetite in order to avoid being overweight or obese. Slow eating also has the effect of increasing postprandial energy expenditure (diet-induced thermogenesis). It is still unclear whether this is due to oral stimuli; that is, the duration of tasting food in the mouth and the duration of chewing. To investigate the effects of oral stimuli on diet-induced thermogenesis in 11 healthy normal weight males, we conducted a randomized crossover study comprising three trials: (1) drinking liquid food normally, (2) drinking liquid food after tasting, and (3) adding chewing while tasting. Oral stimuli (i.e., the duration of tasting liquid food in the mouth and the duration of chewing) significantly increased diet-induced thermogenesis after drinking liquid food. This result demonstrates that the increase in diet-induced thermogenesis is due to oral stimuli rather than the influence of the food bolus. Increased diet-induced thermogenesis induced by chewing and taste stimuli may help to prevent overweight and obesity.

Association of number of bites and eating speed with energy intake: Wearable technology results under free-living conditions

Personalized weight management strategies are gaining interest. However, knowledge is limited regarding eating habits and association with energy intake, and current technologies limit assessment in free-living situations. We assessed associations between eating behavior and time of day with energy intake using a wearable camera under free-living conditions and explored if obesity modifies the associations. Sixteen participants (50% with obesity) recorded free-living eating behaviors using a wearable fish-eye camera for 14 days. Videos were viewed by trained annotators who confirmed number of bites, eating speed, and time of day for each eating episode. Energy intake was determined by a trained dietitian performing 24-h diet recalls. Greater number of bites, reduced eating speed, and increased BMI significantly predicted higher energy intake among all participants (P < 0.05, each). There were no significant interactions between obesity and number of bites, eating speed, or time of day (p > 0.05). Greater number of bites and reduced eating speed were significantly associated with higher energy intake in participants without obesity. Results show that under free-living conditions, more bites and slower eating speed predicted higher energy intake when examining consumption of foods with beverages. Obesity did not modify these associations. Findings highlight how eating behaviors can impact energy balance and can inform weight management interventions using wearable technology.

Eating and drinking habits and its association with obesity in Japanese healthy adults: retrospective longitudinal big data analysis using a health check-up database

Few longitudinal studies have evaluated the association between eating and drinking habits and the risk of obesity. Therefore, we conducted a 5-year longitudinal big data analysis for evaluating various eating and drinking habits and the risk of obesity. We analysed individuals without obesity who received medical check-ups from 2008 to 2012 and 5 years later from the JMDC Health check-up database. The primary outcome was the incidence of obesity (BMI ≥ 25 kg/m2), and the secondary outcome was the incidence of abdominal obesity (waist circumference ≥ 85 cm for men and 90 cm for women). Age- and sex-adjusted, and multivariate logistic regression analyses were conducted. Of 123 182 individuals without obesity at baseline, the median age was 45 (interquartile range 40, 51) years and 76 965 (62·5 %) were men. After 5 years, 7133 (5·8 %) people developed obesity and 12 725 (10·3 %) people developed abdominal obesity. Among six eating and drinking habits, skipping breakfast was associated with a higher risk of obesity (OR 1·21; 99 % CI 1·10, 1·34). In contrast, occasional (OR 0·86; 99 % CI 0·78, 0·94) or daily (OR 0·79; 99 % CI 0·68, 0·91) drinking of alcoholic beverages was associated with a lower risk of obesity. According to the 5-year longitudinal data, eating and drinking habits such as mild to moderate alcohol consumption and avoiding skipping breakfast may result in better obesity prevention. However, excess alcohol consumption would be harmful and should be avoided.

Self-Reported Eating Speed Is Associated with Indicators of Obesity in Adults: A Systematic Review and Meta-Analysis

Eating speed (ES) as a dietary behaviour has become a widely discussed factor for weight management and obesity. This study analysed the relationship between ES and anthropometric indicators of obesity, including BMI and waist circumference (WC) in adults. A search conducted of PubMed, Web of Science, Science Direct and Scopus found six longitudinal studies and fifteen cross-sectional studies published for further analysis. A quality assessment was performed with the MINORS checklist. Eight studies were included in the meta-analysis and almost all reviewed studies showed that ES was associated with BMI, and non-fast eaters had significantly lower BMI than fast eaters. Therefore, it was assumed that slowing down the ES may be an effective strategy for weight management and lowering obesity risk. There was also an association between WC and ES. Assessment of eating speed can be included in nutrition surveys to analyse obesity risk. More broadly, research is also needed to establish a validated and standardised methodology to determine eating speed. Further research needs to examine the links between eating speed, obesity, ethnicity, sex, food culture and chronic diseases.

Association Between Eating Speed and Metabolic Syndrome: A Systematic Review and Meta-Analysis

Objective: This review aimed to systematically summarize and meta-analyze the association between eating speed and metabolic syndrome (MetS). Methods: Following the Preferred Reporting Items for Systematic Reviews, and Meta Analyses (PRISMA) guidelines, four electronic databases (PubMed, Web of Science, MEDLINE, and EMBASE) were searched until March 2021 to identify eligible articles based on a series of inclusion and exclusion criteria. Heterogeneity was examined using I ² statistics. Using random-effects models, the pooled odds ratios (ORs), and 95% CIs were calculated to evaluate the association between eating speed with MetS and its components, including central obesity, blood pressure (BP), high-density lipoprotein cholesterol (HDL), triglyceride (TG), and fasting plasma glucose (FPG). Results: Of the 8,500 original hits generated by the systematic search, 29 eligible studies with moderate-to-high quality were included, involving 465,155 subjects. The meta-analysis revealed that eating faster was significantly associated with higher risks of MetS (OR = 1.54, 95% CI: 1.27-1.86), central obesity (OR = 1.54, 95% CI: 1.37-1.73), elevated BP (OR = 1.26, 95% CI: 1.13-1.40), low HDL (OR = 1.23, 95% CI: 1.15-1.31), elevated TG (OR = 1.29, 95% CI: 1.18-1.42), and elevated FPG (OR = 1.16, 95% CI: 1.06-1.27) compared to eating slowly. Conclusions: The results of the review indicated that eating speed was significantly associated with MetS and its components. Interventions related to decreasing eating speed may be beneficial for the management of MetS. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021242213, identifier: CRD42021242213.

Impact of income and eating speed on new-onset diabetes among men: a retrospective cohort study

OBJECTIVE

To examine the impact of income and eating speed on new-onset diabetes among men.

DESIGN

This was a retrospective cohort study.

SETTING

We used the administrative claims and health check-up data for fiscal years 2010-2015 obtained from the Fukuoka branch of the Japan Health Insurance Association.

PARTICIPANTS

Participants were 15 474 non-diabetic male employees, aged between 40 and 74 years. They were categorised based on their eating speeds (ie, fast, normal and non-fast).

PRIMARY AND SECONDARY OUTCOME MEASURES

To calculate the OR of the development of diabetes, we created generalised linear regression models with diabetes onset as the dependent variable and eating speed and income as covariates and calculated corresponding 95% CI values. The analyses were performed after adjusting the data for age, obesity and comorbidities.

RESULTS

Of the total participants, 620 developed diabetes during the 5-year study period. A univariate analysis using the generalised linear regression model revealed that eating fast (OR: 1.35, 95% CI 1.17 to 1.55) and having a low income wereincome (OR: 1.47, 95% CI 1.24 to 1.74) were significantly associated with the onset of diabetes. After adjusting for age, obesity and comorbidities, both eating fast (OR: 1.17, 95% CI 1.02 to 1.35) and having a low income (OR: 1.24, 95% CI 1.03 to 1.50) were recognised as independent risk factors for diabetes onset.

CONCLUSIONS

The study revealed that eating fast and having a low income were independent risk factors, leading to the development of diabetes. While it is difficult to address income differences, it may be possible to address the factors that contribute to income differences to manage diabetes appropriately and at low healthcare costs. However, eating speed can be controlled. Hence, the provision of education and coaching on dietary habits, including eating speed, may be effective in preventing diabetes onset.

Association between eating behaviors and depressive symptoms in Chinese adults: a population-based cross-sectional study

Eating behaviors are associated with health outcomes. However, data regarding the association between eating behaviors and depressive symptoms in Chinese adults are limited. We hypothesized that Chinese adults with problematic eating behaviors would likely have depressive symptoms compared to those with good eating behaviors. We included 1,998 participants (aged 25-68). Logistic regression models were used to estimate odds ratios and 95% confidence intervals for the association between eating behaviors and depressive symptoms. Eating behaviors were assessed using a self-administered questionnaire. Depressive symptoms were assessed using the Self-Rating Depression Scale. In the final adjusted model, the odds ratios and 95% confidence intervals for depressive symptoms were 1.23 (0.99-1.53) and 1.30 (0.97-1.74) when a slow eating rate was compared to medium and fast eating rates, respectively and were 1.35 (1.08-1.68) and 1.40 (1.07-1.83) when breakfast consumers were compared to occasional consumers and skippers, respectively. Eating quickly and skipping breakfast were associated with an increased risk of depressive symptoms. These results suggest that eating behaviors may affect mental health in adults.

Automatic Detection of Chewing and Swallowing

A series of eating behaviors, including chewing and swallowing, is considered to be crucial to the maintenance of good health. However, most such behaviors occur within the human body, and highly invasive methods such as X-rays and fiberscopes must be utilized to collect accurate behavioral data. A simpler method of measurement is needed in healthcare and medical fields; hence, the present study concerns the development of a method to automatically recognize a series of eating behaviors from the sounds produced during eating. The automatic detection of left chewing, right chewing, front biting, and swallowing was tested through the deployment of the hybrid CTC/attention model, which uses sound recorded through 2ch microphones under the ear and weak labeled data as training data to detect the balance of chewing and swallowing. N-gram based data augmentation was first performed using weak labeled data to generate many weak labeled eating sounds to augment the training data. The detection performance was improved through the use of the hybrid CTC/attention model, which can learn the context. In addition, the study confirmed a similar detection performance for open and closed foods.

Relationship between chewing features and body mass index in young adolescents

BACKGROUND

Behavioural aspects of chewing may influence food intake, nutritional status and in turn body weight.

OBJECTIVES

The current study aimed to study chewing features in adolescents as they naturally occur in home-based settings, and to test for a possible association with weight status.

METHODS

Forty-two adolescents (15.3 ± 1.3 years) were recruited (21 with healthy-weight/21 with overweight). Using a smartphone-assisted wearable electromyographic device, the chewing features of each participant were assessed over one evening, including the evening meal, in their natural home setting.

RESULTS

The mean (±SD) for chewing pace was 1.53 ± 0.22 Hz, chewing power 30.1% ± 4.8%, number of chewing episodes 63.1 ± 36.7 and chewing time 11.0 ± 7.7 minutes. The chewing pace of the group with overweight was slower than that of healthy weight (-0.20 Hz; 95% CI, -0.06 to -0.33; P = .005) while their chewing time was shorter (-4.9 minutes; 95% CI, 0.2-9.7; P = .044). A significant negative correlation was observed between BMI z-score and chewing pace (R = -.41; P = .007), and between BMI z-score and chewing time (R = -0.32; P = .039).

CONCLUSION

The current study suggests that adolescents who are overweight eat at a slower pace for a shorter period of time than their counterparts who are a healthy weight. This unexpected finding based on objective data appears to conflict with existing questionnaire findings but provides impetus for further work testing the effectiveness of changing eating behaviour as a weight-management intervention in youth.

Eating Speed and Incidence of Diabetes in a Japanese General Population: ISSA-CKD

Background: We investigated whether eating speed was associated with the incidence of diabetes in a Japanese general population. Methods: A total of 4853 Japanese individuals without diabetes at baseline were analyzed. Self-reported eating speed was categorized as slow, medium, and fast on the basis of questionnaire responses. The study outcome was the incidence of diabetes. Results: After an average follow-up period of 5.1 years, 234 individuals developed diabetes. The incidence of diabetes per 1000 person-years was 4.9 in the slow eating speed group, 8.8 in the medium eating speed group, and 12.5 in the fast eating speed group, respectively (*** p < 0.001 for trend). The HRs were 1.69 (95%CI 0.94–3.06) for the medium eating speed and 2.08 (95%CI 1.13–3.84) for the fast eating speed, compared to the slow eating speed (* p = 0.014 for trend) after adjustment for age, gender, smoking status, drinking, exercise, obesity, hypertension, and dyslipidemia. Conclusion: Faster eating speed increased a risk for the incidence of diabetes in a general Japanese population.

Fast Eating Is Associated with Increased BMI among High-School Students

Fast self-reported eating rate (SRER) has been associated with increased adiposity in children and adults. No studies have been conducted among high-school students, and SRER has not been validated vs. objective eating rate (OBER) in such populations. The objectives were to investigate (among high-school student populations) the association between OBER and BMI z-scores (BMIz), the validity of SRER vs. OBER, and potential differences in BMIz between SRER categories. Three studies were conducted. Study 1 included 116 Swedish students (mean ± SD age: 16.5 ± 0.8, 59% females) who were eating school lunch. Food intake and meal duration were objectively recorded, and OBER was calculated. Additionally, students provided SRER. Study 2 included students (n = 50, mean ± SD age: 16.7 ± 0.6, 58% females) from Study 1 who ate another objectively recorded school lunch. Study 3 included 1832 high-school students (mean ± SD age: 15.8 ± 0.9, 51% females) from Sweden (n = 748) and Greece (n = 1084) who provided SRER. In Study 1, students with BMIz ≥ 0 had faster OBER vs. students with BMIz < 0 (mean difference: +7.7 g/min or +27%, p = 0.012), while students with fast SRER had higher OBER vs. students with slow SRER (mean difference: +13.7 g/min or +56%, p = 0.001). However, there was “minimal” agreement between SRER and OBER categories (κ = 0.31, p < 0.001). In Study 2, OBER during lunch 1 had a “large” correlation with OBER during lunch 2 (r = 0.75, p < 0.001). In Study 3, fast SRER students had higher BMIz vs. slow SRER students (mean difference: 0.37, p < 0.001). Similar observations were found among both Swedish and Greek students. For the first time in high-school students, we confirm the association between fast eating and increased adiposity. Our validation analysis suggests that SRER could be used as a proxy for OBER in studies with large sample sizes on a group level. With smaller samples, OBER should be used instead. To assess eating rate on an individual level, OBER can be used while SRER should be avoided.

The Significant Association between Health Examination Results and Population Health: A Cross-Sectional Ecological Study Using a Nation-Wide Health Checkup Database in Japan

In Japan, population health with life expectancy (LE) and healthy life expectancy (HALE) as indicators varies across the 47 prefectures (administrative regions). This study investigates how health examination results, including attitude toward improving life habits, are associated with population health. The association between health checkup variables and summary population health outcomes (i.e., life expectancy and healthy life expectancy) was investigated using a cross-sectional ecological design with prefectures as the unit of analysis. The medical records, aggregated by prefecture, gender, and age in the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open Data Japan, were used as health checkup variables. Body weight, blood pressure, liver enzymes, drinking habits, smoking habits, diabetes, serum lipids, and answers to questions regarding attitude toward improving health habits were significantly correlated to population health outcomes. Multiple regression analysis also revealed significant influence of these variables on population health. This study highlights that health examination results, including attitude toward improving health habits, are positively associated with population health. Consequently, implementing measures to improve health habits in response to the examination results could help the population maintain a healthy life.

Reliability of a novel wearable device to measure chewing frequency

Purpose In recent years, the chewing frequency, i.e., the number of chewing cycles, has decreased owing to changes in dietary habits. Although these changes may be related to complete body health, there is no evidence-based tool to measure the dietary habits. We developed a small ear-hung wearable device for monitoring mastication behavior. The device, worn on the ear pinna, allows the counting of the number of chewing cycles, and data are collected on a smartphone via Bluetooth. In this study, the reliability of the novel device was verified.Methods A total of 22 healthy volunteers participated in the study. During measurement, the subjects wore the novel wearable device on their right ear pinna and were asked to chew gum, gummy jellies, and rice balls. The number of chewing cycles was counted by the device. A mandibular kinesiograph (MKG) was also recorded, and the chewing activity was recorded as a video. The accuracy, precision, and recall of the ear-hung device were calculated by comparing the data obtained from the MKG and the video recording. Additionally, the factors affecting reliability were examined.Results The accuracy, precision, and recall of the novel device were 101.6 ± 13.6%, 85.3 ± 11.0%, and 84.5 ± 9.5%, respectively. Although the accuracy was not affected by any factor, precision and recall of the novel device for women were significantly worse than that for men, and were greatest when the subjects were chewing gum.Conclusions Our findings suggest that the newly developed ear-hung wearable device for counting the number of chewing cycles was sufficiently reliable.

[Effect of eating speed modification techniques and strategies on food or energy intake: a systematic review and meta-analysis]

Introduction

Scientific evidence indicates that eating slowly reduces food and energy intake. However, few investigations have studied the effect of techniques and strategies that modify eating speed on intake. The objective of this study is to analyze the relationship between these techniques and food and/or energy intake. Therefore, a systematic review of 15 human studies and a meta-analysis of 7 studies with 11 experimental and 1 observational manipulations were carried out. Only the results of two conditions were included, "slow" vs. "fast" of eating speed and ingestion. The estimation of the effect was expressed in OR with a 95 % CI under a random effects model, and heterogeneity was assessed with I2. Publication bias was also assessed with a funnel plot and Egger's linear regression test. The results indicate that eating slowly is a protective factor (OR = 0.73) from excessive intake. Additionally, eating small bites with a small spoon (OR = 0.315), serving food preparations on separate plates (OR = 0.860 and OR = 0.831), using a vibrotactile feedback fork (OR = 0.847), and eating hard-textured foods (OR = 0.831) are the techniques and strategies that modify eating speed and decrease food or energy intake. The present study confirms the premise that eating slowly can reduce excessive food and energy intake.

Combined Impact of a Faster Self-Reported Eating Rate and Higher Dietary Energy Intake Rate on Energy Intake and Adiposity

Eating more quickly and consuming foods with a higher energy-intake-rate (EIR: kcal/min) is associated with greater energy intake and adiposity. However, it remains unclear whether individuals who eat more quickly are more likely to consume foods with higher EIR. We investigated the overlap between self-reported eating rate (SRER) and the consumption of higher EIR foods, and their combined impact on daily energy intake and adiposity in a population-based Asian cohort (n = 7011; 21-75y). Food consumption was assessed using a validated Food Frequency Questionnaire. Moderated regression with simple slope analysis was conducted to evaluate whether SRER modified the association between dietary EIR and total dietary energy intakes. Faster eaters consumed a significantly higher proportion of energy from higher EIR foods among overweight individuals, but not among normal-weight individuals. Associations between dietary EIR and total energy intake were stronger among medium (β = 15.04, 95%CI: 13.00-17.08) and fast (β = 15.69, 95%CI: 12.61-18.78) eaters, compared with slower eaters (β = 9.89, 95%CI: 5.11-14.67; p-interaction = 0.032). Higher dietary EIR also tended to be more strongly associated with BMI in fast eaters (β = 0.025, 95%CI: 0.011-0.038) than in slow eaters (β = 0.017, 95%CI: -0.007-0.040). These findings suggest that the combination of eating more quickly and selecting a greater proportion of energy from higher EIR foods (i.e., softly textured, energy dense), promoted higher dietary energy intakes and adiposity.

Eating Fast Has a Significant Impact on Glycemic Excursion in Healthy Women: Randomized Controlled Cross-Over Trial

Epidemiological studies have shown that self-reported fast eating increases the risk of diabetes and obesity. Our aim was to evaluate the acute effect of fast eating on glycemic parameters through conducting a randomized controlled cross-over study with young healthy women. Nineteen healthy women wore a flash glucose monitoring system for 6 days. Each participant consumed identical test meals with a different eating speed of fast eating (10 min) or slow eating (20 min) on the 4th or the 5th day. The daily glycemic parameters were compared between the 2 days. The mean amplitude of glycemic excursion (MAGE; fast eating 3.67 ± 0.31 vs. slow eating 2.67 ± 0.20 mmol/L, p < 0.01), incremental glucose peak (IGP; breakfast 2.30 ± 0.19 vs. 1.71 ± 0.12 mmol/L, p < 0.01, lunch 4.06 ± 0.33 vs. 3.13 ± 0.28 mmol/L, p < 0.01, dinner 3.87 ± 0.38 vs. 2.27 ± 0.27 mmol/L, p < 0.001), and incremental area under the curve for glucose of dinner 2 h (IAUC; 256 ± 30 vs. 128 ± 18 mmol/L × min, p < 0.001) for fast eating were all significantly higher than those for slow eating. The results suggest that fast eating is associated with higher glycemic excursion in healthy women.

Incidence of severe hypoglycemia and its association with serum adiponectin in Japanese patients with type 1 and insulin-treated type 2 diabetes: The Fukuoka Diabetes Registry

AIMS/INTRODUCTION

The incidence of severe hypoglycemia and its risk factors including an insulin-sensitizing adipokine, adiponectin, were prospectively investigated in Japanese patients with type 1 or insulin-treated type 2 diabetes.

MATERIALS AND METHODS

A total of 207 participants with type 1 diabetes (mean age 55 years) and 1,396 with insulin-treated type 2 diabetes (mean age 65 years) from the local diabetes registry were followed for 5 years (follow-up rate 99%). Severe hypoglycemia was defined as events requiring the assistance of others for recovery from hypoglycemia.

RESULTS

The incidence of severe hypoglycemia was 9.2 per 100 person-years in those with type 1 diabetes, and 2.3 per 100 person-years in those with insulin-treated type 2 diabetes, respectively. For type 1 diabetes, the risk was significant in those with a history of severe hypoglycemia within the previous year, slow eating and higher serum adiponectin (the highest vs the lowest in quartile hazard ratio 2.36, 95% confidence interval 1.22-4.69). For insulin-treated type 2 diabetes, the risk included age ≥65 years, history of severe hypoglycemia within the previous year, alcohol consumption ≥60 g/day, larger insulin dose and higher serum adiponectin (the highest vs the lowest in quartile, hazard ratio 2.95, 95% confidence interval 1.22-4.69). For all participants, the incidence of severe hypoglycemia increased along with serum adiponectin (age- and sex-adjusted hazard ratio 1.65 per 1 standard deviation increase of log serum adiponectin, 95% confidence interval 1.45-1.87).

CONCLUSIONS

The incidence of severe hypoglycemia was prospectively determined, and the association between severe hypoglycemia and higher serum adiponectin was observed in Japanese patients with type 1 and insulin-treated type 2 diabetes.

Association between eating speed and newly diagnosed nonalcoholic fatty liver disease among the general population

Fast eating speed is a risk factor for obesity, which is also closely related to nonalcoholic fatty liver disease (NAFLD), suggesting that fast eating speed may contribute to the development of NAFLD. But the extent to which obesity may mediate the association between eating speed and NAFLD is uncertain. We hypothesized that obesity plays a mediating role in the association between eating speed and prevalence of NAFLD in the general population. A cross-sectional study (n = 23,611) was conducted in a general population sample from Tianjin, China. We measured anthropometrics and biochemical variables. The self-reported eating speed per meal was recorded and classified into 4 categories: slow, medium, relatively fast, and very fast. NAFLD was diagnosed by liver ultrasonography. Multiple logistic regression analysis was used to assess the associations between the eating speed and the prevalence of NAFLD, as well as the mediation effects of obesity on the association between eating speed and NAFLD. The prevalence of newly diagnosed NAFLD was 19.0%. After adjusting for potentially confounding factors, the odds ratios (95% confidence interval) of NAFLD across categories of eating speed were 1.00 (reference), 1.39 (1.18-1.64), 1.71 (1.45-2.01), and 2.04 (1.70-2.46). All these significant odds ratios were attenuated to be nonsignificant by adjustment for body mass index and/or waist circumference. This is the first study to demonstrate that eating speed is not independently associated with increased risk of NAFLD.

How Important Is Eating Rate in the Physiological Response to Food Intake, Control of Body Weight, and Glycemia?

The link between eating rate and energy intake has long been a matter of extensive research. A better understanding of the effect of food intake speed on body weight and glycemia in the long term could serve as a means to prevent weight gain and/or dysglycemia. Whether a fast eating rate plays an important role in increased energy intake and body weight depends on various factors related to the studied food such as texture, viscosity and taste, but seems to be also influenced by the habitual characteristics of the studied subjects as well. Hunger and satiety quantified via test meals in acute experiments with subsequent energy intake measurements and their association with anorexigenic and orexigenic regulating peptides provide further insight to the complicated pathogenesis of obesity. The present review examines data from the abundant literature on the subject of eating rate, and highlights the main findings in people with normal weight, obesity, and type 2 diabetes, with the aim of clarifying the association between rate of food intake and hunger, satiety, glycemia, and energy intake in the short and long term.

The associations of specific school- and individual-level characteristics with obesity among primary school children in Beijing, China

OBJECTIVE

We aimed to investigate the associations between school-level characteristics and obesity among Chinese primary school children with consideration of individual-level characteristics.

DESIGN

This cross-sectional study was conducted in 2015/2016. School-level characteristics were assessed using an interviewer-administered school questionnaire, and a 'school-based obesity prevention index' was further developed. Individual-level characteristics were collected by self-administered questionnaires. Objectively measured height and weight of students were collected, and obesity status was classified according to the International Obesity Task Force criteria for Asian children. Generalised linear mixed models were used to estimate the associations among the school- and individual-level characteristics and obesity of students.

SETTING

Thirty-seven primary schools from an urban and a rural district of Beijing, China.

PARTICIPANTS

School staffs, 2201 students and their parents.

RESULTS

The school-based obesity prevention index involved the number of health professionals, availability of students' health records, monitoring students' nutrition status, frequency of health education activities, reporting achievements of obesity prevention activities to parents, duration of physical activity during school time and availability of playground equipment. The prevalence of obesity was lower in schools with the higher index value compared with that in schools with the lower index value (OR 0·56; 95 % CI 0·40, 0·79). Some individual-level characteristics were negatively associated with childhood obesity: liking sports, duration of screen time ≤2 h/d, perceived lower eating speed, parental non-overweight/obesity.

CONCLUSIONS

Irrespective of individual-level characteristics, the specific school-level characteristics had a cumulative effect on obesity among Chinese primary school children. Further school-based obesity intervention should consider these characteristics simultaneously.

Association Between Self-Reported Eating Rate, Energy Intake, and Cardiovascular Risk Factors in a Multi-Ethnic Asian Population

Eating faster is associated with greater body mass index (BMI), but less is known about the relationships between eating rate, energy intake, body composition, and cardio-metabolic risk factors in different Asian ethnic groups. Using data from the Singapore Multi-Ethnic Cohort (n = 7011; 21-75 y), we investigated associations between self-reported eating rate (SRER), with energy intake, body composition, blood pressure, and blood lipids. SRER and lifestyle was assessed using interviewer-administered questionnaires. Multivariable models were used to examine the associations of SRER with energy intake, body composition, blood pressure, and blood lipids after adjusting for covariates. General and abdominal overweight were defined as BMI ≥ 23 kg/m² and waist circumference > 90cm (men) and > 80cm (women), respectively. On average, faster eaters (vs. slower eaters) consumed 105kcal/day more (p = 0.034), had ~5kg higher body weight (p < 0.001), 1.3 kg/m² higher BMI (p < 0.001), and 3.1cm larger waist-circumference (p < 0.001). Faster eaters had significantly higher blood pressure, circulating triglycerides, and total-to-high-density lipoprotein cholesterol ratio than slower eaters. Faster eaters were twice as likely to develop general (multivariable-OR: 2.2;95%CI,1.8-2.6; p < 0.001), and abdominal (OR:1.8;95%CI, 1.5-2.2; p < 0.001) overweight than slower eaters. This association was observed across all subgroups by age, sex, and ethnicity. Findings suggest that SRER is a robust behavioral marker for increased risk of higher energy intake, obesity, and poor cardio-metabolic health, and a modifiable behavioral risk-factor for obesity prevention.

Relationship of sociodemographic and lifestyle factors and diet habits with metabolic syndrome (MetS) among three ethnic groups of the Malaysian population

Objectives

Literature shows a high prevalence of MetS among Malaysians, varying across the major ethnicities. Since sociodemographic characteristics, lifestyle factors and diet habits of such communities have been reported to be diverse, the objective of this study was to investigate the association of various sociodemographic characteristics, lifestyle factors and diet habits with MetS overall, as well as with the three major ethnic communities in Malaysia, specifically.

Materials and methods

We conducted a cross-sectional study among 481 Malaysians of ages 18 years and above living in the state of Johor, Malaysia. Information on demographics, lifestyle and diet habits were collected using a structured questionnaire. Harmonized criteria were used to assess the status of MetS. Multiple logistic regression was employed to determine any associations between sociodemographic and lifestyle factors and dietary behaviours with MetS.

Results

MetS was found among 32.2% of the respondents and was more prevalent among the Indians (51.9%), followed by the Malays (36.7%) and the Chinese (20.2%). Overall, increasing age (AOR = 2.44[95%CI = 1.27–4.70] at 40–49 years vs. AOR = 4.14[95%CI = 1.97–8.69] at 60 years and above) and Indian ethnicity (AOR = 1.95[95%CI = 1.12–3.38)] increased the odds of MetS, while higher education (AOR = 0.44[95%CI = 0.20–0.94] decreased the odds of MetS in this population. Quick finishing of meals (AOR = 2.17[95%CI = 1.02–4.60]) and low physical activity (AOR = 4.76[95%CI = 1.49–15.26]) were associated with increased odds of MetS among the Malays and the Chinese, respectively.

Conclusion

The population of Johor depicts a diverse lifestyle and diet behaviour, and some of these factors are associated with MetS in certain ethnic groups. In the light of such differences, ethnic specific measures would be needed to reduce the prevalence of MetS among those in this population.

Association between intensive health guidance focusing on eating quickly and metabolic syndrome in Japanese middle-aged citizens

PURPOSE

The purpose of this intervention study was to investigate whether intensive health guidance focusing on eating quickly can prevent metabolic syndrome (MetS) more effectively than standard routine guidance in Japanese citizens living in rural areas.

METHODS

This controlled, non-randomized, intervention study analyzed 141 participants with MetS at baseline. Participants in the intervention group received health guidance focusing on eating quickly and standard health guidance about MetS in accordance with the guidelines of the Ministry of Health, Labour and Welfare in Japan, whereas participants in the control group received only standard health guidance about MetS. The primary study outcome was the prevalence of MetS at a 1-year follow-up.

RESULTS

At 1-year follow-up, the prevalence of MetS in the intervention group was significantly lower than that in the control group (p = 0.003). The decreases in body weight, body mass index, waist circumference and triglycerides from baseline to 1 year were significantly greater in the intervention group than in the control group (p < 0.05).

CONCLUSION

Intensive health guidance focusing on eating quickly is more effective for improving MetS than standard Japanese health guidance alone.

LEVEL OF EVIDENCE

Level II, Evidence obtained from well-designed controlled trials without randomization. TRIAL REGISTRY NAME, REGISTRATION IDENTIFICATION NUMBER, AND URL FOR THE REGISTRY: UMIN, UMIN000030600, http://www.umin.ac.jp/ctr/index-j.htm.

Gum chewing while walking increases fat oxidation and energy expenditure

[Purpose] Although gum chewing while walking has been reported to increase walking speed and heart rate, its effect on energy expenditure remains unclear. The purpose of the present study was to investigate the effects of gum chewing while walking on fat oxidation, energy expenditure, and different walking parameters. [Participants and Methods] This randomized crossover study included 10 males and 5 females who walked for 15 min at their own pace while chewing 2 pieces of gum in the gum trial or while eating 2 tablets in the control trial. A wearable metabolic system, heart rate monitor, and pedometer measured fat oxidation, energy expenditure, heart rate, step count, and walking distance. Walking speed and stride length were also calculated. [Results] The energy expenditure, fat oxidation and heart rate were significantly higher during the gum trial than during the control trial. Significant increases were observed in the step count, walking distance, and walking speed but not in the stride length. [Conclusion] Our results suggest that gum chewing affects sympathetic nervous system activity and walking rhythm with a consequent improvement in the health-related effects of walking, which in turn helps to maintain weight. These findings may play a role in preventing the gradual age-related weight gain that predisposes to obesity.

Systematic estimation of BMI: A novel insight into predicting overweight/obesity in undergraduates

The prevalence of overweight-obesity has increased sharply among undergraduates worldwide. In 2016, approximately 52% of adults were overweight-obese. This cross-sectional study aimed to investigate the prevalence of overweight-obesity and explore in depth the connection between eating habits and overweight-obesity among Chinese undergraduates.The study population included 536 undergraduates recruited in Shijiazhuang, China, in 2017. They were administered questionnaires for assessing demographic and daily lifestyle characteristics, including sex, region, eating speed, number of meals per day, and sweetmeat habit. Anthropometric status was assessed by calculating the body mass index (BMI). The determinants of overweight-obesity were investigated by the Pearson χ test, Spearman rho test, multivariable linear regression, univariate/multivariate logistic regression, and receiver operating characteristic curve analysis.The prevalence of undergraduate overweight-obesity was 13.6%. Sex [male vs female, odds ratio (OR): 1.903; 95% confidence interval (95% CI): 1.147-3.156], region (urban vs rural, OR: 1.953; 95% CI: 1.178-3.240), number of meals per day (3 vs 2, OR: 0.290; 95% CI: 0.137-0.612), and sweetmeat habit (every day vs never, OR: 4.167; 95% CI: 1.090-15.933) were significantly associated with overweight-obesity. Eating very fast was positively associated with overweight-obesity and showed the highest OR (vs very slow/slow, OR: 5.486; 95% CI: 1.622-18.553). However, the results of multivariate logistic regression analysis indicated that only higher eating speed is a significant independent risk factor for overweight/obesity (OR: 17.392; 95% CI, 1.614-187.363; P = .019).Scoremeng = 1.402 × scoresex + 1.269 × scoreregion + 19.004 × scoreeatin speed + 2.546 × scorenumber of meals per day + 1.626 × scoresweetmeat habit and BMI = 0.253 × Scoremeng + 18.592. These 2 formulas can help estimate the weight status of undergraduates and predict whether they will be overweight or obese.

Insulin and incretin hormone responses to rapid versus slow ingestion of a standardized solid breakfast in healthy subjects

People with repeated rapid meal ingestion have been reported to have increased risk of insulin resistance, impaired glucose tolerance and obesity. To explore whether speed of eating a breakfast influences the postprandial rise of glucose, insulin and the incretin hormones, 24 healthy subjects (12 men and 12 women, mean age 62 years) ingested a standardized solid breakfast consisting of 524 kcal (60% from carbohydrate, 20% from protein, 20% from fat) over 5 or 12 minutes on separate days in random order. Breakfast ingestion increased circulating glucose and insulin with maximal levels seen at 30 minutes after start of meal ingestion with no significant difference in the two tests. Similarly, breakfast increased circulating levels of total (reflecting secretion) glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) with, again, no difference between the tests. Furthermore, gastric emptying, as revealed by the indirect paracetamol test, did not differ between the tests. We therefore conclude that the speed of breakfast ingestion does not affect the postprandial rise of glucose, insulin or incretin hormones in healthy subjects.