A recent editorial questioned whether body mass index (BMI) was truly an accurate measure of health, since the formula which calculates obesity based on weight and height leaves a number of factors unaccounted for. Now, a new study supports the opinion of the editorial’s authors, because it found that many people can be both “fat and fit” if they have low levels of inflammation, rendering them metabolically healthy.

People whose BMI is 30 and above are considered obese, which has long been associated with inflammation and a higher risk for heart disease, high blood pressure, diabetes, gallstones, breathing problems, and some cancers. But the study found that lower levels of some inflammatory markers, including C-reactive protein (CRP), TNF-alpha, and IL-6 could still make someone metabolically healthy, even with an obese BMI — 35 percent of obese people don’t have metabolic health disorders, HealthDay News reported.

“In our study, metabolically healthy people — both obese and non-obese — had lower levels of a range of inflammatory markers,” the study’s lead author Catherine Phillips, of University College Cork, Ireland, said in a news release.

Phillips and her team looked at data regarding 2,040 people between 45 and 74 years old who were involved in the Cork and Kerry Diabetes and Heart Disease Study, which tested for prevalence of metabolic syndrome. Participants were surveyed about their lifestyles, and underwent physical exams and blood tests to measure BMI, metabolic profiles, and levels of inflammation.

The researchers found that metabolically healthy obese and non-obese participants had lower levels of complement component 3 (C3), CRP, TNF-aplha, IL-6, and plasminogen inhibitor-1 (PAI-1). They also had higher adiponectin levels — an anti-inflammatory hormone — and a lower white blood cell count, which is usually elevated in response to inflammation, according to MedPage Today. Metabolically healthy obese patients with lower C3 levels were between two and three-and-a-half times more likely to have good metabolic health, depending on which definitions were used.

“From a public health standpoint, we need better methods for identifying which obese people face the greatest risk of diabetes and heart disease,” Phillips said in the press release. “Inflammatory markers offer a potential strategy for pinpointing people who could benefit most from medical interventions.”

With regards to who is likely to have good metabolic health, even when obese, Kristin Kirkpatrick, a dietician with the Cleveland Clinic, told Everyday Health that much of it can be attributed to diet.

“What you eat can cause inflammation. If your diet consists of lots of vegetables, fruits, and other healthy foods, you’re going to have less inflammation than if you ate a lot of sugar," she said. “We don’t want to give people an excuse to be fat, but there’s more to your health than just weight.”

 

Source: Phillips C, Perry I. Does Inflammation Determine Metabolic Health Status in Obese and Nonobese Adults? Journal of Clinical Endocrinology and Meteabolism. 2013.