Researchers also found that replacing carbohydrates with protein and fat from animal sources was associated with a higher risk of mortality than moderate carbohydrate intake whereas replacing with plant-based foods was linked to a lower risk of mortality.
People with low carb diets (meaning less than 40% of their calories came from carbohydrates) and high carb diets (more than 70% of their calories came from carbs) had a higher risk of mortality than those with a moderate carb intake (50-55% of calories).
Seidelmann suggested that, "instead, if one chooses to follow a low-carbohydrate diet, then exchanging carbohydrates for more plant-based fats and proteins might actually promote healthy aging in the long term".
Middle-aged people who get roughly half their daily calories from carbohydrates live several years longer on average than those with meat-heavy low-carb diets, researchers reported Friday.
"Those that favoured plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter, and whole-grain breads, were associated with lower mortality", it said, adding that this suggested "the source of food notably modifies the association between carbohydrate intake and mortality".More news: New MacBook, iPad Pro, and AirPower Coming in September
In the new study, the researchers examined information from almost 15,500 adults ages 45 to 64 from four communities in North Carolina, Mississippi, Minnesota and Maryland. Eating moderate levels between that range offered the best options for a healthy lifespan.
However, she said, "our data suggests that animal-based low-carbohydrate diets, which are prevalent in North America and Europe, might be associated with shorter overall life span and should be discouraged".
Those with high-carb diets even managed to outlive those with low-carb diets by three years, while those with moderate carbohydrate consumption outlived those with low-carb by four years.
From this, scientists estimated the proportion of calories they got from carbohydrates, fats, and protein.
Eating a low-carb diet might help you lose weight now.More news: Fulham - Premier League - 18 August 2018
In the study, published in The Lancet Public Health, 15,400 people from the United States filled out questionnaires on the food and drink they consumed, along with portion sizes. Diets that involved replacing carbs with proteins and fats from animal sources, including beef, lamb, pork, chicken and cheese, were linked with a greater risk of death.
The researchers then pulled data from seven other studies, as well as their own study, to perform a separate analysis involving more than 432,000 people in 20 countries.
Professor Nita Forouhi, from the University of Cambridge's MRC Epidemiology Unit, said: "A really important message from this study is that it is not enough to focus on the nutrients, but whether they are derived from animal or plant sources".
But weight loss plans like the Atkins diet which replace starchy foods with animal protein and fat from meat and dairy products lower life expectancy.
However, there are limitations to the study.More news: Tom Brady, Nick Foles finally connect after missed Super Bowl handshake
Catherine Collins, an NHS dietitian, said: "No aspect of nutrition is so hotly contended on social media than the carb versus fat debate, despite the long term evidence on health benefits firmly supporting the higher carb argument". The food questionnaire in the study may have also led some people to underestimate the calories and fat they had eaten.