- Being overweight is dangerous, as it can increase the risk of death
- Individuals who have a higher Body Mass Index (BMI) are at a greater risk of death
- Currently, doctors advice to maintain a normal BMI of between 18.5 and 25
In the last few years, the harmful effects of being overweight have been underestimated. However, it was found that being overweight can increase the risk of death, reveals a new study.
The new study analyzed BMI, health and mortality data in about 60,000 parents and their children to examine the influence of obesity and risk of death.
‘Being overweight is not healthy and doctor's advice to maintain a BMI of between 18.5 and 25.’
The University of Bristol study was published in the International Journal of Epidemiology.
Link Between Parent's BMI and Children's BMI
In previous studies, doctors who recommended BMI and compared the risk of death appears to be above the range. However, doctors claimed that it is good to be mildly overweight for overall health.
However, scientists were suspicious of these studies, as they do not reflect the true effects of BMI on health. Early stages of illness, health-damaging behaviors like cigarette smoking were can lead to lower BMI and increased risk of death.
It becomes difficult to estimate the influence of BMI on the risk of death. This research study aims to assess the association between BMI and risk of death.
Using HUNT, the Bristol Medical School team along with their co-workers from the Norwegian University of Science and Technology, were able to observe how mortality in the parents and their adult children was affected due to BMI.
BMI of Children, Not Influenced by Parents
HUNT is a Norwegian population-based health cohort study, which was based in a rural county with about 130,000 residents.
BMI of parents and their children are related due to their genetic factors. BMI of children is an indicator of the BMI of their parents.
The BMI of adult children is not influenced by their parent's illnesses. Hence, using offspring BMI can avoid problems that can be inherited from their parents and to their risk of death.
The health records were examined of around 30,000 mother and the research team assessed child pairs and 30,000 father and child pairs. They examined the extent to which BMI can influence mortality risk and illness that can lead to low BMI rather than BMI influencing illness.
Findings of this Study
The results showed that when the offspring BMI was used instead of their parent's BMI, it was found that the harmful effects of low BMI were reduced. They also found the detrimental effects of high BMI were much higher when compared to those found in the conventional analyses.
Most importantly, the research team suggests that previous studies have underestimated the harmful effects of being overweight.
The research team in this study support the doctor's advice in maintaining a BMI of between 18.5 and 25.
The fact that being overweight may be healthy was proven to be just a myth.
Dr. David Carslake, the study's lead author and Senior Research Associate from the MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, said: "An alarming increase in obesity levels across the world which have risen from 105 million in 1975 to 641 million in 2014, according to a recent Lancet study, create concern about the implications for public health.
"This study demonstrates that correlation is not causation and that when it comes to public health recommendations, we need to be cautious interpreting data based on associations alone. We found that previous studies have underestimated the impact of being overweight on mortality and our findings support current advice to maintain a BMI of between 18.5 and 25."
Professor George Davey Smith, Director of the MRC IEU and Professor of Clinical Epidemiology, University of Bristol, added that they are used to seeing different studies indicating that something is good or bad for our health.
The previous studies come from naïve observational studies, which could be misleading.
Further research is required for identifying the causal effects of factors influencing health. Elements that were applied in this study are necessary to make recommendations for public health based on reliable evidence.