“Constant Cravers are hungry the whole time,” says van Tulleken, “and like to snack on things high in sugar and fat.” They enjoy their food and think about it a lot, grazing throughout the day. Soon after a hearty lunch, this group was offered a range of foods and given a gadget that they squeezed to measure how tempting they found each item. The Cravers all wanted naughty-but-nice sausage rolls and cupcakes more than the other groups.
Certain genes interfere with the brain’s understanding of our fat reserves, explains Dr Giles Yeo, a genetics researcher at the Medical Research Council. If it thinks we have less fat than we actually do, it tells us to keep on eating – a basic survival mechanism. All the Constant Cravers tested positive for these genes.
Losing weight is hardest for Constant Cravers. The answer is intermittent fasting – better known as the 5:2 diet, when you eat normally (but healthily) for five days a week and then reduce calorie intake to 800 on the other two days. This makes the body burn up its fat stores.
Result: Average weight loss 1st 1lb
For Sharon Ferreira, “Food is like a secret partner that no one else knows about, nobody else sees me with.” Like all Constant Cravers, Sharon found the diet a challenge – she lost 6lb – but knowing this is related to her genes has helped her to understand why.
What’s the Right Diet for You? A Horizon Special begins on BBC2 tonight (12th January) at 9.00pm