Experts have long warned that putting on weight is dangerous for health but the new research reinforces the theory that the part of the body where fat accumulates has a major impact.
Putting on weight around the hips is actually safer than if it accumulates around the belly or is stored around major organs such as the liver or pancreas, the scientists found.
The research team, from the University of Cambridge, found some women are genetically less able to store fat at the hips.
Lead author Dr Luca Lotta, of the Medical Research Council Epidemiology Unit in Cambridge said: ‘It may seem counter-intuitive to think that some people with less fat around their hips are at higher risk of diabetes or heart disease.
‘We believe that this is due to a genetically-determined inability to store excess calories safely in the hip region as opposed to elsewhere.
‘This means that individuals with this genetic make-up preferentially store their excess fat in the liver, muscles or pancreas, or in their blood in the form of circulating fats and sugar, any of which can lead to a higher disease risk.
‘We are trying to understand whether some of the genes identified by our study may be suitable targets for future drug development but this process may take several years.’
The research team, whose findings are published in the JAMA medical journal, studied the genetic profiles of more than 600,000 women.
They identified two specific groups of genetic variants – one that lowers fat around the hips, and another increasing fat around the waist and belly.
‘Genetics which specifically change fat distribution by lowering fat storage around the hips increase risk of disease independent of, and in addition to, mechanisms that affect abdominal fat storage.’
The team also conducted detailed assessments of fat distribution among 18,000 people using X-ray scans that can distinguish body fat from muscle and bones.
Dr Langenberg added: ‘Not all apple shapes are the same.
‘Guidelines that focus solely on measuring waist circumference to assess risk overlook people whose body shape is not adequately captured by this metric but who are still likely to develop cardiovascular and metabolic diseases.
‘Carrying excess weight around the hips is a metabolically safer way of storing fat but those who aren’t genetically predisposed to doing so would benefit greatly from lifestyle interventions, such as restricting their calorie intake or increasing their physical activity.’