There has been a lot of talk back and forth about the benefits or risks to following low-carb diets. The United States Department of Agriculture suggests that everyone follow the MyPlate system, which recommends that around 30% of your plate be built on carbs. This advice has been the staple for years. The old Food Pyramid suggested 6-11 servings of grains, rice, and pasta, up to 50% of your daily intake. And doctors have warned people away from low-carb diets for years, saying they weren’t balanced.

But lots of new research is saying low-carb diets could actually be highly beneficial for losing weight, reducing cholesterol levels, and improving blood sugar.

A 2013 review of 20 studies found that low-carbohydrate, Mediterranean, and high-protein diets could improve blood sugar, aid weight loss, and increase HDL (good) cholesterol. Another 2008 review found that the low-carb, high-protein approach to weight loss was highly effective, not only at reducing cardiovascular disease, but at helping people maintain their diet when compared to people on a high-carb, low-fat diet.

However, many of these studies were done only over a 6-month or 12-year period. What happens when you follow a low-carb diet in the long run?

Unfortunately, this 2013 review suggests there may be more to lose than gain with low-carb diets. In their analysis of 17 studies, researchers found that low-carb diets were associated with a higher risk of mortality (even though the risk of mortality from cardiovascular disease may have been lower)!

To understand what’s happening here, we need to go back to the motivations for people following low-carb diets. Ten years ago, it was called the Atkins diet. Now, it’s the “Paleo” diet, or “caveman” diet or “hunter-gatherer” diet. These latest versions base their food choices on the idea that humans didn’t evolve to eat grains, dairy, processed foods, or sugar. The bulk of the diet is composed of animal products and the rest from plant foods. Carbs have very little place here.

However, the whole idea is based on a false premise: mainly, the idea that humans reached some sort of evolutionary peak when we were hunter-gatherers. It also proposes that early humans didn’t eat grains, had less calcium in their diet, less fiber, and so on. This site lays it all out in a handy side-by-side comparison. But new research is finding out that paleolithic man may not have been so different from us after all.

They ate grains, drank alcohol, and even though they didn’t drink milk, they got plenty of calcium from foods such as shellfish.

Other than having an effect on blood sugar and other cardiovascular outcomes, having too much fat and not enough carbs can make you sleepy, affecting both how alert you are during the day and how well you sleep at night.

The biggest danger with low-carb diets is that many people following it tend to substitute one bad habit for another. Instead of balancing their diet and making sure to cut calories without losing nutrients, followers of fad diets can often end up eating too many fats or not enough protein. With the Atkins diet, it’s easy to eat tons of low-carb processed or restaurant foods that offer few natural vitamins or nutrients. On the Paleo diet, you may miss out the nutrients found in forbidden healthy foods such as low-fat yogurt, beans, or grains.

Ultimately, low-carb diets can help you lose weight, but they may not be worth it. For some people, finding the right balance of eating enough protein, fiber, and vegetables to stay full and energized is the key to losing weight. But for most people, you’d be better off with lowering the overall calories you eat, eating more healthy and unprocessed foods, and adding exercise to your regime to lose weight.

Read more about fasting for weight loss and the best amount of time to work out.