Scientists have shed light on why some people can eat whatever they want and never gain weight.
hey are known as the “superlean”, with a BMI of less than 18.5.
Until now, it was believed that these individuals were more physically active and therefore burned more calories, according to researchers at the University of Aberdeen.
But they found that super-slim people actually exercise less than their normal-weight counterparts and eat about 12 percent less than people with a normal BMI.
Another unexpected result of the study was that super-lean individuals had a much higher-than-expected metabolism when they were at rest, which the researchers said was linked to higher levels of circulating thyroid hormones.
An added surprise was that in super-skinny people, their cholesterol and triglyceride profiles were indicative of good cardiovascular health.
Scientists hadn’t expected this, given how inactive they were, and suggested their low activity may have been offset by their lean body composition.
Professor John Speakman, who led the study, said: “The results came as a real surprise.
“When people talk to super-skinny individuals, they say they can eat whatever they want, but our work showed that what they actually eat is much less than people with a normal BMI range.”