Staging Obesity-Related Health Risks
To address these problems, Sharma and his team developed a scale, from 0 to 4, that stages overweight and obese people in much the same way that oncologists stage cancer.
In both systems, stage 1 or 2 isn't as life threatening as stage 3 or 4.
The stage largely depends on how many other health problems are present with the extra weight.
For example, a person at stage 1 on the EOSS might be obese with borderline high blood pressure or prediabetes. They could also have occasional aches and pains, fatigue, or they might get short of breath after mild physical activity, like climbing a flight of stairs.
A person at stage 3, on the other hand, might be the same size, but they've already had a heart attack or stroke, they can't move around very well, and they may have poor quality of life.
To test the tool, the researchers applied it to nearly 8,000 Americans who took part in the government's ongoing National Health and Nutrition Examination Surveys (NHANES) from 1988 to 2004.
Each person who met the definition of being overweight, meaning they had a height and weight that gave them a BMI over 25, was also given an EOSS score.
The stages were assigned based on whether they also had diabetes, high blood pressure, high cholesterol, osteoarthritis, liver or kidney disease, trouble moving around, metabolic syndrome, and a large waist and high triglycerides.
A person's size, the study found, wasn't a very good predictor of how healthy they were.
More than three-quarters of the overweight and obese people in the study received scores of 1 or 2 on the EOSS scale.
And when researchers cross-referenced their work against death records, they found that BMI wasn't a reliable predictor of a person's death risk, but their EOSS score was.
About 90% of people who were classified as stage 1 when they started the study, for example, were still alive more than 17 years later, compared to roughly 55% of people who were at EOSS stage 3.
Compared to people with an EOSS score of 0 or 1, meaning they had few health problems, those at stage 2 had a roughly 60% increased risk of death, and those at stage 3 had nearly three times the risk of dying over the next 20 years.