For years, dieters have had to deal with many conflicting advice on how to eat.
First, fat was the bad guy. Then it was considered ideal to avoid sugar and become low on carbohydrates.
Recently, dieters who tried the trendy ketogenic diet have discovered that if they replace carbohydrates with fat, they can drop their body into a natural starvation mode and lose weight, while still enjoying bacon and sipping heavy cream.
But a new, long-term study published on Thursday in The Lancet suggests that there might be a winning formula for the amount of carbohydrates consumed every day. It is based on some very unsexy, old advice: everything in moderation.
Lead researcher Sara Seidelmann, cardiologist and nutrition researcher at Brigham and the women's hospital in Boston, told Business Insider that her results suggested that a diet "rich in vegetable-rich foods such as vegetables, whole grains, legumes and nuts, associated is with healthy aging. "
This usually means that about half of the calories you eat per day should come from carbohydrates.
A Goldilocks rule for carbohydrates
For the study, Seidelmann looked at the diet of more than 15,400 adults in the US and another 432,000 people in more than 20 countries around the world. She and her team of researchers analyzed this information in relation to how long the study participants lived.
They discovered that people who ate a moderate amount of carbohydrates – about half of their daily calories – had the tendency to live the longest.
People who took more than 70% of their energy out of carbohydrates or used less than 40% of their daily calories from carbohydrates, on the other hand, had more chance of dying than people who ate something.
It is a sort of Goldilocks finding: we should not eat too much carbohydrate, not too little, but just the right amount.
On one side of the spectrum are people who suffer from the consequences of eating too many carbs, as in some low-income countries where people tend to count on white rice for food without much else on their plate.
On the other hand, people consume little carbohydrates. Surprisingly, the group with the highest mortality probability in the American study was those who did not eat carbohydrates, because these people tended to replace carb-heavy foods with animal fats and proteins: "beef, pork, lamb, chicken and cheese," as Seidelmann put it.
"It is clear that filling your plate with those things increased mortality," she said.
In fact, the researchers concluded that a 50-year-old who eats 50-55% carbohydrate margin could expect to live another 33.1 years, while someone of the same age who takes only 30% of his calories from carbohydrates would expect to live about 29.1 years longer.
The most important thing is to get as much healthy and whole food as possible on your plate
There is a way to make a low-carbohydrate diet and age well: people who ate small amounts of carbohydrates, but more vegetable proteins like vegetables beans and nuts were found to die less quickly and tended to live on a mature age.
This may be because eating large amounts of animal fat and protein, but little fresh vegetable food can increase the inflammation in the body.
"Try to make choices that fill your plate with plants," said Seidelmann.
She agrees that there is a short-term link between low-carbohydrate diets and weight loss, but warns that diets such as keto and Atkins may not be great long-term strategies.
"There is absolutely nothing more important to our health than what we eat every day," she said. "I really want people to realize the power they have for their own health," she said.