How does body mass index (BMI) develop over the course of life? What are the trends from generation to generation? And how does race, education and social class affect body weight? An American study answers these questions using longitudinal data for peers since the 1890s. Accordingly, the average BMI of each generation was higher than the previous one. In addition, the body weight of those born later increases rapidly at a young age. The problems are especially severe among blacks and Hispanics as well as people with low levels of education.
Overweight, obesity and related health risks are a problem for more and more people in industrialized nations. In the US, more than 70 percent of all adults had a body mass index of over 25 in 2016 and were therefore considered overweight. From an epidemiological point of view, the increasing proportion of overweight children and adolescents is a particular cause for concern, as people who are too obese at a young age often have difficulties achieving a healthy weight even as adults. . How BMI develops during life and which trends can be observed from generation to generation has not yet been systematically recorded.
BMI grows stronger and faster
A team led by Yang Claire Yang from the University of North Carolina has now evaluated four large longitudinal studies in the US based on this information. They were able to access data from approximately 65,000 respondents between the ages of 11 and 107. They divided into a five-year swamp according to their time of birth and individually analyzed BMI for each birth time. In addition, they evaluated parental ethnicity, educational level, and educational level for all respondents and related these influential factors to BMI.
The researchers said in the report, “Among younger-born peers, BMI was higher than average and increased faster than previously-born peers.” While those born between 1950 and 1954 had an average BMI of 25.8 at age 30, which corresponds to slightly overweight, the BMI for those born between 1980 and 1984 was 30.2, therefore in the area of obesity. In addition to birth peers, researchers observed the trend that BMI increases from adolescence to adulthood, and increases among younger peers. Between a maximum of 50 and 69 years, body weight decreases below the age of 70, for example as a result of illnesses.
As influencing education and ethnicity factors
Yang and his colleagues identified parents’ level of education and their own educational qualifications as important influencing factors. “Higher educational qualifications of parents and respondents were associated with lower BMI values across all age groups,” they write. “For women whose parents had a university degree, the average BMI increase during their lives was even lower.”
According to the analysis, ethnicity also played a role: “Compared to whites, blacks and Hispanics had a significantly higher BMI value earlier in life, which remained intact across all age groups,” the researchers said. The differences are only partly due to socio-economic status. “One possible mechanism for this disparity in the BMI curriculum is that the burden of discrimination and differential access to health resources leads to the fact that the biological aging process accelerates or minority lower health than whites -Display Increasing Behavior “, Explain. Author. The stress of everyday discrimination alone can have a negative effect on weight and health.
The effect of racial and educational differences was more pronounced in younger peers. Researchers see a worrying trend here, but there are also possibilities of retaliation. “This study identifies adolescence and young adulthood as an important time window in which obesity can rapidly increase and in which racial and educational disparities arise that freeze into adulthood,” they write. That is why it is especially important to start with prevention programs here.
Quelle: Yang Claire Yang (University of North Carolina at Chapel Hill, USA) et al., Proceedings of the National Institute of Studies, doi: 10.1073 / pars.2020167118