Diet sodas may not be helping you lose weight—in fact, these and other artificially sweetened foods may sabotage your diet by confusing and rewiring your brain’s reward centers. This study from the journal Physiology & Behavior is yet another example of how lifestyle choices can alter your brain—negatively or positively.
Scanning diet soda drinkers’ brains
The University of San Diego study followed 24 young adults: half the group drank at least one serving of diet soda every day, while the other half avoided the artificially sweetened drinks. These adults were then hooked up to brain scanning equipment while scientists fed them water alternately flavored by natural and artificial sweeteners—then the researchers sat back and watched what unfolded in the brain.
Artificial sweeteners confuse reward
Diet soda drinkers who consumed a greater number of diet sodas had reduced activation in a part of the brain responsible to signaling reward and controlling food intake.
Because sweetness was no longer a reliable indicator of incoming calories, the brain had trained itself to respond less in the face of sweet flavors. This threw off normal predictions about calories and energy, making it more likely that diet soda drinkers people would consume additional calories later in the day.
These findings may provide some insight into the link between diet soda consumption and obesity.