When you lose weight, where does all that lost fat actually go? Most doctors, dieticians and personal trainers who were polled reckon it converts into energy or heat-but they're wrong. In fact, it disappears into thin air because we breathe it out as carbon dioxide.
For every 10 kilograms of weight that is lost, 8.4 kg is exhaled, and the remainder becomes water, which we excrete, says an essay from the University of New South Wales in Australia.
Yet fewer than 50 per cent of a group of 150 doctors, dieticians and personal trainers got the answer right when they were polled by researchers. Instead, they thought the excess fat was converted to heat or energy, but physicist and TV science presenter Ruben Meerman points out the answer violates the law of conservation of mass. "The misconceptions we have encountered reveal surprising unfamiliarity about basic aspects of how the human body works," said Mr Meerman.
(Source: British Medical Journal, 2014; 349: g7257)