More Years of Obesity Leads to Higher Risk for Disease, Research Shows
A huge volume of research has established links between obesity and several potentially serious health conditions, including Type 2 diabetes, high blood pressure, high cholesterol, and atherosclerosis (where fatty deposits narrow the arteries)—all of which can lead to coronary heart disease and stroke (known as a cardiometabolic disease). But a new study from the U.K., published December 8 in PLOS Medicine, found an association between the length of time a person is obese and a greater risk for cardiometabolic disease.1
Tom Norris, Ph.D., and his colleagues at Loughborough University in England analyzed data from three British birth cohort studies that collected information on body mass index from age 10 -40, involving 20,746 participants. The cohort studies also provided information on cardiometabolic disease risk factors, such as blood pressure, cholesterol, and glycated hemoglobin (blood sugar).
More years of obesity was associated with worse outcomes (levels of blood pressure, high-density lipoprotein cholesterol, and glycated hemoglobin) for all measured cardiometabolic risk factors. The association was particularly strong for glycated hemoglobin (HbA1c), a test to measure how well someone is managing their diabetes.
People with fewer than five years of obesity had a 5% higher HbA1c compared with people who had never been obese. And those who had been obese for 20-30 years had a 20% higher HbA1c than people who had never been obese.
Our results suggest that the number of years a person lives with their BMI above the obesity threshold increases their diabetes risk. — Tom Norris, PhD
“Our results suggest that the number of years a person lives with their BMI above the obesity threshold increases their diabetes risk,” says Norris, a senior research associate in epidemiology and biostatistics. This was the case even if their BMI was only just in the obesity range, and didn’t continue to increase.
However, the researchers actually expected to see worse outcomes among people who had been obese for longer. Another surprise was that the association of obesity duration with glycated hemoglobin was still largely present after accounting for obesity severity (i.e., the extent to which someone’s BMI is above the obesity threshold). “This was not what we found for the other outcomes,” Norris explains.
What Is Obesity?
The Centers for Disease Control and Prevention (CDC) describes obesity as a weight that is much higher than what is considered a healthy weight for a given height.2 The screening tool for obesity is the Body Mass Index (BMI), which is a person’s weight in kilograms divided by the square of their height in meters. If your BMI is 30.0 or higher, it falls into the obese category.
Obesity exacerbates tendencies to atherosclerosis, which are changes in vascular plaque. This can lead to diabetes or insulin resistance. — Leonard Pianko, MD
However, the CDC stresses that while BMI can be used as a screening tool, it doesn’t determine the body fatness or overall health of an individual. A complete picture of a person’s health is best achieved following all appropriate assessments by a trained health care provider.
“Obesity exacerbates tendencies to atherosclerosis, which are changes in vascular plaque,” says Aventura, Florida cardiologist Leonard Pianko, MD. “This can lead to diabetes or insulin resistance.”
Being obese can also lead to poorly controlled blood pressure, Dr. Pianko continues. “This can result in blood clots, which could potentially cause a stroke,” he explains.
Why Is This New Study Important?
It’s typical for a person to stay obese once they become obese, Norris says. So it follows that a person who becomes obese in childhood is likely to have worse cardiometabolic health in later life than someone who became obese later in life.
“This is paired with an obesity epidemic in the U.K., characterized by children becoming obese at younger ages,” Norris adds. “So, with all of this in mind, we believe a big focus needs to be made on tackling childhood obesity, which in turn will reduce a person’s lifetime duration and thus lower the risk for an adverse cardiometabolic profile in adulthood.”
The researchers recommend that regular routine BMI measurements are taken by healthcare providers, especially during childhood and adolescence, to help identify individuals demonstrating patterns of BMI development that are likely to culminate in obesity.
We believe a big focus needs to be made on tackling childhood obesity, which in turn will reduce a person’s lifetime duration and thus lower the risk for an adverse cardiometabolic profile in adulthood. — Tom Norris, PhD
“What we have shown is that the longer a person is obese, the worse their cardiometabolic outcomes are,” Norris says. This demonstrates the importance of delaying the onset of obesity. “However, if you do become obese, it is possible to reduce your cardiometabolic disease risk,” Norris adds.
What This Means For You
When it comes to weight management, commitment, a healthy diet, and regular exercise are key. Beyond that, a plan should be adapted to suit the individual. “The best approach is one that is going to work for you in the long run,” Dr. Pianko says. He recommends figuring out your likes and dislikes, identifying your weaknesses and strengths, finding a diet buddy who will encourage and cheer you on, or looking for a professional to guide you, then adding in an exercise program.
It might not be easy, but it’s definitely worth it. “By controlling your weight through diet and exercise, you can lower your blood pressure and cholesterol, thereby lowering your risk for a stroke,” Dr. Pianko says.