Most of us have been raised thinking that it's the fat, and not the carbs that will make us get overweight. In fact, as a young girl, I rarely ate bacon and other fat-rich foods because my parents did not want me to be unhealthy. Now, of course eating too much bacon isn't that great for us, but it turns out there's something that could be more harmful than unhealthy fats: carbohydrates.

Recently there was a study done in 18 countries that disproved everything we have been raised to believe: that fat is causing all of the problems. Well, what if we told you that too many carbohydrates are causing the real issues?

It turns out that refined, processed carbs are not only bad for us, they are leading us to an early grave.

A large, 18-country study may turn current nutritional thinking on its head.

The new research suggests that it's not the fat in your diet that's raising your risk of premature death, it's too many carbohydrates — especially the refined, processed kinds of carbs — that may be the real killer.

The research also found that eating fruits, vegetables and legumes can lower your risk of dying prematurely. But three or four servings a day seemed to be plenty. Any additional servings didn't appear to provide more benefit.

People with a high fat intake — about 35 percent of their daily diet — had a 23 percent lower risk of early death and 18 percent lower risk of stroke compared to people who ate less fat, said lead author Mahshid Dehghan. She's an investigator with the Population Health Research Institute at McMaster University in Ontario.

At the same time, high-carb diets — containing an average 77 percent carbohydrates — were associated with a 28 percent increased risk of death versus low-carb diets, Dehghan said.

All foods contain three major macronutrients essential for life — fat, carbohydrate and protein. The optimum amounts a person should eat has been the focus of debate for decades, with the pendulum swinging from low-fat to low-carb diets over time.

The keto diet puts emphasis on eating a low carb diet, and now we know why. Not only can carbs cause us to gain unnecessary weight, but eating too many of them over time can lead to an early death.

So if we can't eat carbs what are we supposed to eat? Well, fruits, vegetables, and legumes are the best, but if you're on the keto diet you need to limit those carbs so be wary of fruit. However, eating plenty of vegetables, legumes, and other healthy fats will get you to where you need to be – healthy and the ability to exist on this earth for years to come.

For more on this study visit CBSNews.