"I just love it," she says. "I crave it, need it. My food tastes better with it."
Talles sounds a lot like an addict. Replace her ever-present glass of Diet Coke with a cigarette, and she'd make a convincing two-pack-a-day smoker. In fact, she says, she buys her 2-liter bottles 10 at a timemore if a hurricane is in the offingbecause if she notices she's down to her last one, she panics "like somebody who doesn't have their pack of cigarettes."
Most diet-soda drinkers aren't as gung ho as Talles, but people who down several diet sodas per day are hardly rare. Government surveys have found that people who drink diet beverages average more than 26 ounces per day (some drink far more) and that 3% of diet-soda drinkers have at least four daily.
Are these diet-soda fiends true addicts? And if so, what are they addicted to? The most obvious answer is caffeinebut that doesn't explain the many die-hard diet drinkers who prefer caffeine-free varieties.
Factors besides caffeine are likely at work. Although diet soda clearly isn't as addictive as a drug like nicotine, experts say the rituals that surround diet soda and the artificial sweeteners it contains can make some people psychologicallyand even physicallydependent on it in ways that mimic more serious addictions. And unlike sugared soda, which will make you gain weight if you drink too much of it, zero-calorie soda doesn't seem to have an immediate downside that prevents people from overindulging.
"You think, 'Oh, I can drink another one because I'm not getting more calories,'" says Harold C. Urschel, MD, an addiction psychiatrist in Dallas and the author of Healing the Addicted Brain. "Psychologically you're giving yourself permission."
How diet soda trains your brain
The simplest explanation for a serious diet-soda habit is caffeine. Many people who chain-drink diet soda may be caffeine addicts who simply prefer soda to coffee or energy drinks, though diet soda doesn't provide much of a kick by comparison. (A can of Diet Coke contains four to five times less caffeine than a small Starbucks coffee.)
Caffeine can't account for Steve Bagi's habit, however. The 44-year-old graphic designer from Chester Springs, Pa., gets his morning buzz from an enormous cup of coffee, yet he still buys caffeine-free Diet Pepsi by the case and downs six cans a day, "easy."
His Diet Pepsi cravings stem from a prior addiction to nicotine, not caffeine. "It's all tied to smoking," says Bagi, who smoked a pack a day for 20 years and started drinking diet soda to mask the aftertaste of cigarettes. He eventually kicked the smoking habitbut the Diet Pepsi one stuck.