A new research, titled, “Metabolically normal obese people are protected from adverse effects following weight gain” suggests obesity does not always imply metabolic changes that lead to diabetes, stroke, or heart disease. The study was published January 2, 2015 in The Journal of Clinical Investigation.
According to the findings of a team of researchers at the Washington University School of Medicine in St. Louis, some of those diagnosed to be clinically obese do not have the tendency to develop the common metabolic abnormalities usually associated with being excessively overweight, such as developing an increased resistance to insulin, having high levels of triglycerides and low levels of HDL cholesterol, excess liver fat and high blood pressure. The obese individuals that did not display these metabolic problems at the beginning of the study did not develop them, despite gaining even more weight.
The study enrolled 20 participants who were determined to be obese. They were then asked to gain 15 pounds over several months in order to allow scientists to understand whether or not the extra weight would affect their metabolic functions. The study’s first author, Elisa Fabbrini, said in a press release: “Our goal was to have research participants consume 1,000 extra calories every day until each gained 6 percent of his or her body weight. This was not easy to do. It is just as difficult to get people to gain weight as it is to get them to lose weight.”
Participants gained weight by consuming high-calorie meals in fast-food restaurants, under a dietitian’s supervision. These restaurants provide rigorously regulated portion sizes, and very detailed nutritional information. Before and after the participants gained weight, they were thoroughly assessed by the researchers and medical professionals.
Fabbrini and her colleagues observed that after gaining weight, the metabolic profiles of obese and metabolically-normal subjects remained the same and normal as they were before; however, those who were already assessed to have these metabolic anomalies manifested a significant worsening of their conditions.
“This research demonstrates that some obese people are protected from the adverse metabolic effects of moderate weight gain, whereas others are predisposed to develop these problems,” said senior investigator Samuel Klein, the director of Washington University’s Center for Human Nutrition. “This observation is important clinically because about 25 percent of obese people do not have metabolic complications. Our data shows that these people remain metabolically normal even after they gain additional weight.”
After the study was concluded, the researchers helped the participants lose the extra weight they had gained. “It’s important to point out that once the study was completed, we enrolled all subjects in our weight-loss program to make sure they lost all of the weight they had gained, or more,” noted Klein.
The presence and amount of fat within the liver and the role of genetics in fat tissue accumulation were some points that seemed to determine the differences between metabolically normal and abnormal patients. “These results suggest that the ability of body fat to expand and increase in a healthy way may protect some people from the metabolic problems associated with obesity and weight gain,” Klein added.
More studies are required to understand the multiple diseases that may be influenced by obesity, and the reason why there are some individuals who are significantly less at risk of developing those same complications. Klein and his team are planning more projects that can bring them closer to those answers.
