The rise of the ketogenic diet has turned much of what people have been taught about healthy eating on its head—and led many of us to question the role of carbohydrates in our diet.
Unsurprisingly, experts and research alike are now digging into low-carb diets. Here, we dive into what low-carb is all about—and whether we should all throw bread out the window.
What’s The Big Deal About Carbs, Anyway?
Before the carb-hating train pulls out of the station, let’s get something straight: Not all carbs are created equal—and not all carbs are evil.
Carbs are not inherently bad for us. It’s just plain fact: Glucose is our body’s preferred source of energy. Our body breaks carbohydrates down into glucose, and then uses that glucose for energy to fuel everything we do, explains dietitian Gabrielle Mancella, R.D.
Research even identifies starchy (a.k.a. carby) plant foods—think root vegetables and potatoes—as essential to human evolution. They’re also credited with protecting health in a number of ways. These foods—called ‘complex carbs’—contain fiber and nutrients, and provide our body with sustainable energy.
Thing is, many of the carbs we eat today look nothing like the carbs our ancestors ate. (Think bread, crackers, and sweetened drinks.)
These refined carbs offer little fiber and nutrition, and are processed by our body quickly, explains dietitian Meghan Lyle, M.P.H., R.D. The result: a vicious cycle of blood sugar spikes and crashes that contribute to cravings, low energy, constipation, weight gain, diabetes, and heart disease over time.
What Does ‘Low-Carb’ Really Mean?
Though many of us might jump right to keto when we think ‘low-carb,’ keto is just one very specific type of low-carb diet.
On keto, you eat 10 percent of your daily calories in carbs. (Most experts recommend sticking to just 20 to 30 grams of net carbohydrates a day!) Keeping carbs that low requires careful planning; after all, just one medium apple packs 25 grams of carbohydrates.
Not all low-carb diets are keto, though.
“Typically, anything less than 100 to 150 total grams of carbohydrates per day is classified low-carb,” says April Bruns R.D.N., L.D., of Clear Springs Foods. That’s about 20 to 30 percent of your daily caloric intake.
FYI: The standard American diet typically consists of 225 to 325 grams of carbs—about 45 to 65 percent of your daily calorie intake.
What A Healthy Low-Carb Diet Looks Like
For many people, going low-carb means swapping sugar for artificial sweeteners and eating more meat, cheese, and processed ‘low-carb’ snacks.
However, if you don’t emphasize clean, whole foods, cutting all the carbs in the world won’t improve your long-term health or disease risk, says Lyle.
A healthy low-carb diet emphasizes a variety of whole foods, like:
- Quality poultry and meat
- Olive oil
- Nuts and seeds
- Leafy greens
- Legumes (beans, lentils, peas)
“The healthiest low-carb diets still allow for whole, complex carbs like beans and fruit,” says Lyle. This way, your low-carb diet still provides the array of micronutrients—like vitamins and minerals—your body needs to function optimally.
Packaged foods labeled ‘low-fat’ or ‘low-carb’? Off the table.
The Benefits Of Going Low-Carb
When done right, a nutrient-dense low-carb diet promotes health and well-being in a myriad of ways.
“If you replace highly processed grains and sugar with healthy fats and lean proteins, you may see improvements in digestion, blood sugar regulation, cholesterol, and cardiovascular health,” says Lyle. After all, the more nutrients your body has to work with, the better.
A Waistline Win
Almost immediately, most low-carb dieters notice weight loss and feel less bloated. Since carbohydrates store water in our muscles and liver, reducing intake causes us to shed water weight, explains Lyle.
The waistline-related benefits don’t end there, either. One 2018 BMJ study found that people who ate low-carb (20 percent of total calories) burned about 250 more calories per day than those who ate higher-carb (60 percent of total calories).
This suggests that reducing carbohydrates may boost your metabolism and support weight loss long-term. For this reason, the study authors suggest going low-carb can even help treat obesity.
Long-Term Health, Boosted
Another win for low-carb diets: In the long run, maintaining a healthy weight reduces our risk for metabolic syndrome, heart disease, and diabetes, says Bruns.
According to Kajsa Ernestam. R.D., dietitian with personalized nutrition app Lifesum, low-carb diets are particularly helpful for managing insulin resistance and type 2 diabetes. “When you eat a lot of nutrient-lacking carbs daily, you require a lot of insulin to keep blood sugar from getting too high, setting you up for insulin resistance,” she says.
Replacing these carbs with nutritious options, though, supports steadier blood sugar levels and slashes risk for insulin resistance. In fact, research suggests low-carb diets can actually reverse type 2 diabetes.
How? Fiber, which supports digestion and healthy blood sugar, plays a big role. And with refined carbs off the table, low-carb eaters (should) rely more on fiber-filled foods like vegetables, fruits, legumes, and nuts.
Case in point: One study published Annals of Internal Medicine found that simply increasing fiber intake to at least 30 grams a day helped folks improve insulin resistance—and blood pressure, too!
Not only does blood sugar stability offer major health benefits through the years, but it also revamps how you feel every single day.
Since you don’t ride the rollercoaster of sugar highs and energy crashes when low-carb, “you can expect to feel more consistent energy, feel more satiated, and experience fewer cravings,” says Chavi Kramer, R.D., dietitian with personalized nutrition company DayTwo.
Is A Low-Carb Diet Right For You?
While low-carb eating can be a game-changer for many people, especially those with blood sugar issues or weight to lose, it may not be appropriate for everyone.
One group that doesn’t do so well on low-carb diets: fitness buffs. Weight-room regulars, bootcamp class lovers, and CrossFitters, that means you. Exercise above a certain intensity (called anaerobic exercise) literally requires carbohydrates to power.
Without adequate carbs in your system, your performance in everything from sprints to big lifts takes a hit. A 2017 report published in Nutrition Today says it best: “To enhance physical performance, high-quality, nutrient-dense carbohydrate sources are still critical.”
Though low-carb may appeal to many women, certified functional medicine practitioner, Terry Wahls. M.D., urges caution—especially to women of reproductive age.
“Going too low-carb sends the signal to the body that there’s not enough nutrition or energy around to reproduce,” Wahls said. This can then throw off women’s (sensitive) hormone function, and even increase risk of infertility.
The Bottom Line
If you’re interested in adopting a low-carb diet (for whatever reason!), Bruns recommends working with a registered dietitian. They can help you understand what balance of carbs, protein, and fat best fits your lifestyle and goals, and create an individualized plan that ensures you get all the vitamins and minerals you need.
Ultimately, the quality of the food you eat matters. Regardless of how many carbs you eat, make sure they come from complex, fiber-, and nutrient-rich foods.