Because carbohydrates, like have been linked with the production of positive mood chemicals in the brain, such as serotonin, he says, "carbs are good mood lifters," Ayoob notes, so it's possible that the lack of carbohydrates themselves affected dieter's mood.
Laura Dolson, online writer and expert on low-carbohydrate dieting, adds that the results may have to do more with individual differences than problems with low-carb living in and of itself.
"Some people are more sensitive to carbohydrates and…these individuals are more likely to respond well to low-carb diets in a lot of ways…they talk about improved energy, improved concentration, and improved mood," she says.
"I've been following people for years on my [low-carb] forum [and] people often report improvement in mood to me."
By randomly assigning participants to the same, restricted amount of carbohydrates and restricting caloric intake, she says the study was "automatically not a standard low-carb diet."
"What makes it work well for people in the long term is that they are allowed to follow the natural amount of food their bodies need" and adjust the level of carbohydrate as needed.
"My take away from this is if you're going to lose the same amount of weight, but you're going to feel better about it on the low-fat…I [would] definitely…recommend the low-fat," Ayoob says, but Lavie points out that the study "did not really show bad moods in the low-carbohydrate group" so these findings "don't support any great harm from the low-carb diet."
For Dungan, ultimately it has been about paying attention to what works for her body. "I tried everything else, for me, [I'm] better off with a low-carb diet…because if I have more carbs…it's just something I can't seem to handle."
"[But] everyone's different," she says. "There are a lot of factors [deciding] how it affects you."