You may look thin and be too fat

Research highlighting the danger of fat around vital organs could change the way we tackle obesity. Professor Jimmy Bell, a molecular imaging expert, and a team of researchers have recently discovered that, in fact, an outwardly trim person can carry a higher proportion of dangerous hidden fat than an overweight one, if that fat is around vital organs. The team has used a magnetic resonance imaging (MRI) scanner at Hammersmith Hospital in London to map the fat distribution of 600 volunteers. Their results suggest that up to four in 10 people could be “tofi” – thin outside, fat inside.

Previous research has shown someone with a lot of internal fat around the liver, gut, heart and pancreas, or streaked through under-used muscles, has a higher risk of heart disease, type 2 diabetes, hypertension and some cancers than someone with high levels of external fat. “Traditional ways of measuring body fat, such as BMI, give people the wrong idea about how much fat they have, as it says nothing about internal storage. People become obsessed by dieting, but doing this without exercise means they may be putting down fat in the wrong places. We want to get away from that and focus on maximising the health benefits of physical activity without dramatic lifestyle changes.”

Simon Relph, a marketing art director from Sydenham, London, and Neil Ferguson, 23, a marketing designer from Bexley Village, Kent, provide a good example of why our current methods of evaluating weight-related health risks are so flawed. Simon, 41, has a BMI of 27.7, but admits to not doing much exercise. His MRI scan shows he is carrying 15 litres of internal fat. His colleague Neil, 23, has a BMI of 28.1. Yet he plays football three to four times a week and goes to the gym regularly. He admits to “love handles” around his waist, but has only four litres of internal fat.

The researchers believe our current view of the relationship between diet, physical activity and health is far too simplistic. This is where the so-called intervention studies being carried out by Prof Bell’s team come in. Groups of individuals will be put through 16-week programmes of exercise of different intensities and frequencies. Their progress will be accurately measured with MRI scans, and compared with control groups. The ultimate objective is to be able to provide far more accurate advice on how someone should exercise, based on their gender, ethnicity and genetic make-up.