Scientists have released the first study to link salt consumption with obesity, claiming an extra gram eaten per day increases the risk of obesity by nearly 30%.

The study, published in the journal Hypertension, claims salt is a cause of obesity regardless of overall calorie consumption, suggesting it negatively impacts the metabolism and therefore the body’s ability to process fat.

Researchers analysed data from 458 children and 785 adults taking part in the UK National Diet and Nutrition Survey’s (NDNS).

The results showed a consistent significant association between salt intake and BMI, waist circumference and body fat mass – independent of total energy intake and sugar-sweetened beverage consumption.

The study found a 1g/day increase in salt intake being associated with an increased risk of being overweight or obese by 28% in children and 26% in adults.

Professor Graham MacGregor, professor of cardiovascular medicine at Queen Mary University of London and chairman of campaign group Consensus Action on Salt & Health (CASH), who led the research, said: “High blood pressure and obesity both lead to the development of cardiovascular disease, stroke, heart attacks and heart failure, which are the commonest causes of death and disability in the UK.

“Obesity also predisposes to type 2 diabetes, which further increases the risks of cardiovascular disease and can lead to severe complications. Such an epidemic will cripple the NHS if the increase in these diet related issues are not stopped immediately.”