The findings suggest trendy weight loss regimes which encourage avoiding bread, potatoes and pasta may do more harm than good.
However, it’s not an excuse to pile your plate with them as the study also found that eating too many carbs damages health.
Instead, it suggests a moderate amount of carbohydrate, around 50 to 55% of your diet, is healthiest. Those whose diet is made up of less than 40% or more than 70% carbohydrate have a higher mortality risk, researchers said.
The study, led by Harvard School of Public Health in the US, goes some way to ending the decades-old debate over whether cutting carbs or fat is a better way to lose weight and improve health.
The Atkins diet is perhaps the best known approach that focuses simply on restricting carbohydrates, with no limits on protein and fat.
However, the new study suggests it is much healthier to follow a balanced diet that combines all nutrients in moderation.
The findings support the advice of Public Health England which says starchy carbohydrates are the main component of a healthy diet.
The scientists looked at data from previous studies, involving 432000 people from 20 countries, which backed up their results. They also found that cutting out carbohydrates posed the greatest risk to health when people replaced them with meat and cheese.
Co-author Dr Sara Seidelmann said: “Low-carb diets that replace carbohydrates with protein or fat are gaining widespread popularity as a health and weight loss strategy. However, our data suggests that animal-based low-carbohydrate diets might be associated with shorter overall life span and should be discouraged.”
The authors tracked 15528 adults aged 45 to 64 over 25 years. Of these, 6283 died.
But those whose carb consumption was low were 20% more likely to die than those with a moderate intake. Researchers therefore estimated that a 50-year-old with a moderate carb intake could expect to live another 33 years. However, a 50-year-old with a low intake could expect to live to 79, while one with a high intake could expect to reach 82.
Co-author Walter Willett, a professor at the Harvard School of Public Health, said: “These findings bring together several strands that have been controversial.
“Too much and too little carbohydrate can be harmful, but what counts most is the type of fat, protein and carbohydrate.”
The findings were also backed by British scientists. Dr Ian Johnson, of the Quadram Institute food research centre in Norwich, said: “These findings emphasise that there is nothing to be gained from long-term adherence to low-carbohydrate diets.”
The study appears in the Lancet Public Health journal.