In my work as a registered dietitian, one of the questions I get most is about low-carb diets. Every person I talk to has a different idea about what “low” means, and every news item I see does, too. Is it no carb? Reduced carb? Keto? Sugar free? Can you totally ignore calories?
Al Roker shared on TODAY that he eats about 100 grams of carbohydrate a day. I’ll bet that doesn’t sound low-carb to a lot of people, but it certainly is. That’s a step toward taking some of the mystery out! Let’s see if we can clear up a little more.
Classifying the main types of diets all comes down to the “macros”— the relative percentages of calories coming from each macronutrient group of proteins, fats, and carbohydrates. In terms of carbohydrates, the main styles are general healthy, ketogenic, and low-carbohydrate — what that study calls the carbohydrate-insulin model.
A general, heart-healthy diet high in whole grains, fruits, and vegetables is often a dietitian’s first pick, because the best-studied human diets that reduce chronic disease risk the most fall into this category. They average about 50% of calories from minimally-processed carbohydrate sources. Even more can be healthy— most good quality plant-based diets will be at least 60% high fiber, with complex carbohydrates.
Conversely, ketogenic diets are extremely low in carbohydrate, requiring fewer than 5% of calories coming from carbs in order to keep you in a special metabolic state called ketosis, which usually results in rapid weight loss. Why not choose that one then? It’s a restrictive format that some people swear by, but for many, it’s a struggle to sustain over the long term. You don’t have to pay much attention to calorie counting, but you do have to pay very close attention to even small amounts of carbs. Some people are concerned about possible negative health effects, find that it doesn’t fit into their social lives, or they just miss bread! About a third of my weight management clients find me after regaining what they lost on keto as they tried to transition to something less extreme, too.
Enter the low- or reduced-carb diet. There’s a lot of variation from person to…