The idea that you can be overweight and possibly obese (a BMI of 30 or higher, a waist that measure more than 35 inches for women), had recently been explored by scientists. Some studies have suggested that nearly 30 percent of obese people are relatively health, meaning able to avoid the likely negative health effects of obesity such as diabetes. A lot of the research has focused on how sensitive the body is to insulin, the hormone that helps the body balance blood sugar.
Yet, after looking specifically at insulin response, a team a researchers report that for in insulin-sensitive obese people, insulin response may not be optimal after all, setting them up for a host of health problems. The study results offer important indicators for black women’s health as four out of five of us are overweight or obese.
In a small study—just 65 people–assessed responses to insulin in 15 healthy, never-obese participants and 50 obese subjects enrolled in a clinical study of gastric bypass surgery. The researchers took biopsies of abdominal white fat tissue before and at the end of a two-hour period of intravenous infusion of insulin and glucose. Based on the glucose uptake rate, the researchers classified 21 obese subjects as insulin sensitive and 29 as insulin resistant.
Surprisingly, mRNA sequencing of white fat tissue samples revealed a clear distinction between never-obese participants and both groups of obese individuals. White fat tissue from insulin-sensitive and insulin-resistant obese individuals showed nearly identical patterns of gene expression in response to insulin stimulation. These abnormal gene expression patterns were not influenced by cardiovascular or metabolic risk factors such as waist-to-hip ratio, heart rate, or blood pressure. The findings show that obesity rather than other common risk factors is likely the primary factor determining metabolic health.
“Our study suggests that the notion of metabolically healthy obesity may be more complicated than previously thought, at least in subcutaneous adipose tissue,” said the study’s lead author, Rydén, Carsten Daub of the Karolinska Institutet in Stockholm, Sweden, in an interview with the journal Cell. “There doesn’t appear to be a clear transcriptomic fingerprint that differentiates obese subjects with high or low insulin sensitivity, indicating that obesity per se is the major driver explaining the changes in gene expression.”
The take home message is that the body may not be able to carry excess weight and remain healthy. To avoid the health risks associated with weight, the goal never has to be becoming thin. For most people, just reducing body weight by 10 percent can improve health.