People with a family history of obesity are more likely to benefit from dieting, a study has found.
The research, published in the BMJ, found those at high genetic risk for obesity were more likely to lose greater amounts of weight and keep excess weight off than those with a low genetic risk.
Scientists categorised a healthy diet as being rich in fruit and vegetables, nuts and whole grains and low in salt, sugary drinks, alcohol and red and processed meats.
Obesity is a complex disorder involving a mix of genes and environmental influences. Previous research has shown that diets high in sugar sweetened drinks and fried foods could increase the genetic associations with higher body weight.
Researchers wanted to know whether following a diet rich in fruit and vegetables and low in processed foods could decrease this genetic association with weight gain.
To investigate further, Dr Lu Qi, Professor of Epidemiology, and other researchers from Tulane University and Harvard University, looked at data from two large studies of US health professionals.
They came up with a genetic risk score for each person by analysing the 77 gene variants associated with body mass index.
Changes in body mass index and weight were calculated every four years.
The participants’ diets were assessed every four years and given scores. After 20 years, the researchers found that following a healthier diet was linked to lowered body mass index and body weight.
The effect of following a healthy diet was more prominent in people at high genetic risk for obesity than those with low genetic risk.
While the research didn’t account for other factors which aid weight loss - such as exercise - the scientists said their findings highlight the importance of sticking to a health diet to prevent weight gain, “particularly in people genetically predisposed to obesity”.