You’ve heard it again and again: diets don’t work. But here’s a new one for you: diets make you dumb. Some diets, that is. No, not metaphorically – literally!

The Monitor on Psychology, a publication of the American Psychological Association, reports in its February issue: “The Adkins diet and other low-carb weight-loss plans may hamper thinking and memory.” “Researchers compared the cognitive skills of 19 female dieters over three weeks and found that during the initial period of carbohydrate elimination for the diet low in carbohydrates, the women performed more poorly on memory-related tasks and had slower reaction times than those following low-calorie diets” (APA Monitor on Psychology, 2009, Vol. 40, No. 2, p. 12; Appetite, Vol. 52, No. 1).

To clarify: the cognitive deficits weren’t necessarily the result of calorie restriction per se but due to a reduction in carbs.

If this finding isn’t the last nail in the coffin of low-carb diets, I don’t know what would be! Thankfully the effects are reversible. Holly Taylor, Ph.D. (Tufts University), the psychologist who conducted the study, reassures low-carb dieters: “Thinking and memory skills returned to normal” once the carbs were reintroduced into the diets (APA Monitor on Psychology, p. 12).

The fact that cognitive deficits (memory decline and slower reaction time) are reversible is certainly reassuring. But let’s face it: weight loss at the cost of mind loss is hardly a sustainable long-term approach!