Laura Schoenfeld: This is an interesting question, and I’m not saying that there aren’t people that will gain fat when they go off their low-carb diet, but if you think about how long it really takes for the body to add fat, you’re not going to see multiple pounds of fat gain within a couple of days. Usually the people that are under the impression that they can’t increase their carbs, it’s because when they eat a little bit more carbs than what they normally would eat, they end up gaining, like, five-plus pounds in a day or two, and they usually panic and say, “This is a sign! This means I can’t eat carbs!”
This, I’m pretty confident, is not going to be coming from body fat. It might be a tiny bit of body fat, but if somebody is gaining, like, five-plus pounds in a day or two, the most likely cause of that is water retention. If somebody is on a very-low-carb diet, they’re going to have almost completely empty glycogen stores, and glycogen itself usually takes up … I think it’s like one to two pounds or something, maybe up to four pounds if somebody has a lot of muscle mass, as far as just the glycogen. And then if you store glycogen, you’re going to be storing a couple of grams of water alongside that glycogen as well.
So if somebody goes from a glycogen-depleted, low-carb-diet state and adds a bunch of carbs in and suddenly their muscles and organs and liver get full of not only glycogen, but also the water associated with that glycogen, they’re going to gain weight pretty quickly within a couple of days. Now again, weight versus body fat is the question, if somebody is actually gaining body fat. Most of the time, it’s water weight.
I work with a lot of disordered eating and amenorrhea and women that have been on low-carb diets for a long time that are having a lot of health issues, and you kind of just have to talk people through it and let them know what they should expect. Let them know that they might gain a couple of pounds when they first switch over. If the person knows what to expect, they may be a little bit less upset by it when it happens. Maybe tell them not to weigh themselves for a week after making the switch, just letting them know that that can happen, that it’s not necessarily body fat and that it will go away after they’ve been eating more carbs for a while.
You want to make sure that the person is exercising. If somebody is super-sedentary, then you definitely don’t want them suddenly eating 200 to 300 grams of carbs in a day. But if somebody is super-active and they’re having a lot of health issues that are stemming from low carb intake, then the goal would be to increase their carbs, maybe like 50 grams a day at a time for a couple of days and then go up another 50 grams. That slow increase will help reduce some of that water retention and weight gain that comes from carbing back up. Just knowing that it’s not body fat and knowing that that’s normal that that happens, I think, can take a lot of the stress out of worrying about the carbs and increasing the carb intake.