For those who have only to look at a slice of cake to put on weight, it will seem incredibly unfair.
But there really are people who can eat what they want without piling on the kilos.
In the largest study of thin people’s genes, researchers at Cambridge University have identified those that may speed up the metabolism or help burn fat quicker, so they can stay slender with no dieting or willpower required.
While many who yearn to be slimmer end up yo-yo dieting, as any weight they lose eventually slips back on, scientists believe their discovery could lead to new drugs which mimic the effects of these “thinness” genes.
In the study, these genes were found in the DNA of more than 1 600 thin but healthy people, including women around a size eight and men with a 90cm waist. In almost two-thirds of them it is believed the genes make them less interested in food.
However, in 40% of the study group, thin people said they loved food and ate whatever they wanted without putting on weight.
Researchers now believe these people have particular genes of their own, and are planning a separate study to see what happens in their bodies when they overeat.
Professor Sadaf Farooqi, senior author of the study from the Wellcome Trust-MRC Institute of Metabolic Science at the University of Cambridge, said: “This is proof there are groups of people who really can eat what they want and stay thin.
“The research shows for the first time that these healthy thin people are generally thin because they have a lower burden of genes that increase a person’s chances of being overweight, and not because they are morally superior.”.
The study was published in the journal Plos Genetics.