Revision of conventional standards to achieve individualized physique assessment based on height and growth characteristics.
- The following is content from the press release -
(Headquarters: Aichi, Japan; President: Yohei Sakakibara), in collaboration with a research group led by Professor Ken Seino of Osaka University's Graduate School of Engineering Science, has begun developing new physique assessment technology based on children's developmental processes, utilizing growth data accumulated in the childcare record application "PiyoLog. Professor Seino's research group has previously pointed out the possibility that the criteria for determining obesity and emaciation in children, which are widely used in Japan and abroad, do not adequately reflect differences in height and skeletal growth. In order to more accurately assess children's healthy growth, it is necessary to collect and analyze growth data on height and weight over time on a large scale, but until now it has been difficult to obtain such data. This joint research aims to establish and validate a new method of body size evaluation that takes into account the child's developmental process, utilizing growth record data entered into the "PiyoLog" childcare record application, which is used by approximately 700,000 people per day. Through this initiative, we aim to realize a society in which all children and families can watch their growth with peace of mind through the realization of growth support based on scientific evidence.
Research Background and Objectives
Although it is the responsibility of society as a whole to watch over the healthy growth of children, scientifically based methods for evaluating obesity and emaciation in children have not yet been fully established. In previous studies, Professor Ken Seino and his research group at the Graduate School of Engineering Science, Osaka University, have revealed that the Body Mass Index (BMI) standard, a body mass index widely used worldwide, does not sufficiently take into account differences in height and the influence of skeletal growth (see [1, 2]). It has been pointed out that the international assessment methods currently in common use create height-dependent biases, such that taller children are more likely to be judged as overweight and smaller children are more likely to be judged as underweight. In other words, the conventional definition of BMI as "weight divided by the square of height" makes it difficult to accurately reflect the diverse body shapes and developmental speed of children in the process of growth.
Even according to the unique domestic standard adopted for school health statistics in Japan, the percentage of children who are judged obese or emaciated fluctuates greatly with age. In particular, the percentage is extremely low in the preschool years, and tends to increase or decrease rapidly around puberty. The international approach to physique assessment is to set standards that are less sensitive to age, but until now, it has not been fully verified whether this variation in the Japanese standards truly reflects the health status of children or is due to an age-dependent bias inherent in the assessment standards themselves. This study addresses this question scientifically. The starting point for this study is to address this question scientifically.
The concept of physique assessment using height and weight is based on the power law (scaling law) discovered about 200 years ago by Adolphe Quetelet, who is called the "father of modern statistics. However, recent research by Seino's laboratory has revealed the existence of a more complex scaling relationship in skeletally growing children, which depends not only on height but also on body size (Reference [1]). This means that weight gain in children is closely related to skeletal development, and the same equation cannot be used to describe the relationship between height and weight in growing children and skeletally mature adults. Therefore, it is not always appropriate to evaluate obesity or thinness using the same criteria as for adults.
To solve these problems and establish a more accurate evaluation method, longitudinal data on the height and weight of a large number of children observed over a long period of time is essential. However, until now, it has been difficult to collect such large-scale data. Ltd., which operates the "PiyoLog" child-rearing recording application used by approximately 700,000 people per day, we have launched a joint research project to analyze large-scale growth data using growth data recorded at home on a daily basis for which consent has been obtained for use in research and development.
This R&D project aims to develop a new developmental assessment method that reflects children's individual growth patterns and physique characteristics, and to correct for the height- and age-dependent biases found in conventional domestic and international standards for determining physique. It is known that thinness and obesity in children are closely related to the risk of poor bone development and lifestyle-related diseases in the future, and accurate assessment of body size according to growth stage is the foundation for long-term health maintenance and preventive medicine. The results of this research are expected to lay a new scientific foundation for understanding obesity and emaciation in children with greater precision, as well as to scientifically support the healthy growth of each individual and establish a system to watch over the healthy development of children in society as a whole.
References
[1] Ogata H, Isoyama Y, Nose-Ogura S, Nagai N, Kayaba M, Kruse JGS, Seleznov I, Kaneko M, Shigematsu T, Kiyono K. Allometric multi-scaling of weight-for Allometric multi-scaling of weight-for- height relation in children and adolescents: Revisiting the theoretical basis of body mass index of thinness and obesity assessment. 19:e0307238 (2024).
[2] Isoyama Y, Nose-Ogura S, Ijitsu MJ, Kruse JGS, Nagai N, Kayaba M, Ogata H, Mangalam M, Kiyono K. Age- and height-dependent bias of underweight and Front Public Health 12:1379897 (2024).
Comments from a representative of PiyoLog Inc. (Yohei Sakakibara, President and Representative Director)]
Although many children's height and weight records have been accumulated in the "PiyoLog," it has been difficult to accurately assess each child's thinness or obesity, as the numbers have only been compared to growth curves.
Through this joint research with Seino Laboratory, Graduate School of Engineering Science, Osaka University, we aim to establish new physique evaluation standards based on more scientific evidence and to provide accurate feedback to users based on these standards.
About Piyorog Inc.
We support child-rearing during infancy by providing "PiyoLog," a child-rearing record application that can be shared by married couples. The application has been highly acclaimed for its easy-to-use user interface (UI) and abundant functions, and has achieved a cumulative total of 5 million downloads. We will continue to provide services that make child-rearing more convenient and secure as a partner in child-rearing.
Location: 2F Kura City, 155-3 Hirokoji-cho, Handa, Aichi, Japan
Representative: Yohei Sakakibara, President and Representative Director
Official site:https://www.piyolog.com/
Professor Ken Seino, Graduate School of Engineering Science, Osaka University, comments
Looking after children's health based on large-scale data analysis is a new challenge that has only just begun. Until now, research on children's health has relied on data collected in limited environments by medical and research institutions. In recent years, however, with the development of data science, there has been an accelerating trend toward utilizing "real-world data" obtained in daily life and sharing the results of such analysis with society as a whole. This research is one of the attempts to be at the forefront of this trend. We hope to contribute to the creation of a society in which all children can grow up healthier by building a new physique assessment system based on scientific evidence, based on growth data recorded daily at home.
[Future development
In the future, we will utilize the growth data accumulated in the "PiyoLog" childcare record application to develop a new physique evaluation model that is less susceptible to the effects of age and height. The results obtained will be systematized as "child growth evaluation standards" and made public in a form that can be widely used at home and in medical and educational settings. In addition, by implementing this evaluation method in the "PiYoLog" application, we will provide a system that allows families to easily monitor their children's growth in a scientific manner.
Furthermore, we plan to verify the medical and physiological validity and clinical significance of the new physique assessment method in collaboration with the International Medical Engineering Information Center (MEI Center) at Osaka University. In this way, we will establish a system of developmental support based on scientific evidence from an approach that integrates medicine and information science, and return the results of our research to society.
