Carbohydrates are a popular villain in diet culture, often used as a term for unhealthy but delicious foods you crave. Even if you’ve never tried a low-carb diet plan, you’re probably familiar with the concept of cutting out bread, pasta, and potatoes to lose weight and/or lower your blood sugar.
While this way of eating can be effective, it’s not a magic bullet—and carbs as a category are not the enemy, says Carolyn Suzy, a registered dietitian and national spokesperson for the Academy of Nutrition and Dietetics.
“Carbohydrates have so many wonderful properties—they’re really the most important source of energy for our brains and bodies,” he says. And because the diet industry has demonized the whole group, sometimes the baby is thrown out with the bathwater.
“When you eliminate high-fiber foods like beans or fruits, you reduce your fiber intake, your vitamin and mineral intake, and you’re at a higher risk of developing certain deficiencies,” she says.
Always talk to your doctor before making drastic changes to your diet to make sure you’re meeting your nutritional needs. However, if a low-carb diet gets the green light, adopt a new meal plan with these considerations in mind.
How low should you go?
The USDA’s Dietary Guidelines for Americans recommend that 45-65% of your daily calories come from carbohydrates. For a 2,000-calorie-a-day diet, that’s about 900-1,300 kcal of carbs, or 225-325 grams of carbs. Low-carb meal plans typically limit carbohydrates to 26% of your daily calories, or less than 130 grams of carbohydrates per day on a 2,000-calorie diet.
But before you take that number and run, it’s important to consider your unique physique. Online calculators like the National Institutes of Health’s Body Weight Planner and the USDA’s MyPlate Plan can give you personalized calorie intake for your height, age, and fitness level, and tell you which food groups to get those calories from. But even then, Susie says there’s more to consider when it comes to eating smart.
“We’re all different than our age, gender, height and activity level, so health conditions are important to consider,” she says. For example, if you are pregnant or breastfeeding, or living with diabetes, your needs will change.
Types of low carb diets
Although there are no end to the different brands and methods of low-carb diets, they generally fall into one of two broad categories: those that lower carbs and increase fat, and those that decrease carbs and increase protein.
Low-carb, high-fat diets, such as the keto diet, focus on foods high in fat, which can serve as extra fuel after your body cuts back on carbohydrates. A typical breakdown for a 2,000 calorie per day diet on the keto plan would be 70-80% fat, 5-10% carbs, and 10-20% protein, or 165 grams of fat, 40 grams of carbs, and 75 grams of protein.
“Being in a state of ketosis varies from person to person,” says Susie. “It might be 30 grams of carbs for me, it might be 40 grams of carbs for you, it might be 50 grams of carbs for my sister. We are all built differently.”
A high-carb, high-fat diet is not a good choice if you have problems with your pancreas, liver, gallbladder, or thyroid, and can cause constipation if you don’t try to eat fiber. Some studies also show that it increases the risk of cardiovascular diseases.
Diets that are lower in carbohydrates and higher in protein usually increase the percentage of protein to the 10%-30% of your daily calories recommended by the Centers for Disease Control and Prevention. The amount you aim for depends on the plan you follow.
If you choose red meat or full-fat dairy for your protein, your risk of heart disease is higher. When your body processes protein, it produces more metabolic waste products, so if you struggle with kidney problems, a high-carb, high-protein diet can put more strain on your system.
Susie says, “It’s always a good idea to work with a registered dietitian to make sure you’re not at risk of vitamin or mineral deficiencies. “But overall I think as long as you’re still eating fresh fruits, fresh vegetables and greens, and you’re not overloading your diet with overly processed foods because of the keto-friendly label, you’re meeting your needs.