This isn’t great news for dieters, but sometimes sugar can be a good thing. Roy Baumeister, a psychologist at Florida State University, had subjects perform a mentally taxing task – watching a video while being careful to ignore random words scrolling across the bottom of the screen. (Apparently, it takes quite a bit of concentration to NOT look at the scrolling words.) Then, the subjects were given a drink of lemonade and asked to perform another cognitively demanding task, choose an apartment based on descriptions of various options.

The catch was that some subjects drank lemonade made with real sugar, and others had lemonade made with Splenda, a sugar substitute without nutritional value. The performance differences on the apartment task were surprising. […]