Diet Soda: Does It Cause Weight Gain?

Most dieters are quite familiar with diet soda. We guzzle diet drinks daily, savoring their flavor while feeling that we’re getting away with something in our diets because they contain zero calories. What a deal, right?

Well, maybe not. A 2005 study found a 41% increase in obesity risk was associated with each serving of diet soda consumed daily.

University of Texas Health Science Center Study

The study, conducted by the University of Texas Health Science Center, studied data on 1,550 Americans ages 25 to 64. The participants were studied for 7 to 8 years. Results showed that total soft drink consumption was tied to increased rates of obesity, but – perhaps surprisingly – participants drinking only diet soda faced the highest obesity rate of all, even greater than that of participants drinking both regular and diet drinks.

Obesity Risk

What exactly is the obesity risk for diet pop drinkers? The study found an obesity risk of 37.5% for those drinking 1/2 to 1 can of diet soda daily, 54.5% risk of obesity for those drinking 1 to 2 cans daily, and a whopping 57.1% risk for those drinking more than 2 diet pops per day.

How Can Diet Soda Cause Weight Gain?

How can something with no calories lead to weight gain? The exact mechanism is unknown, but there are several theories.

One is the possibility that diet soda isn’t causing weight gain so much as accompanying it. You notice you’ve gained a few pounds, so you decide to switch from regular to diet soda. The pounds continue to pile on, but you keep drinking the diet soda, thinking that you’re helping your diet at least a little. In such a situation, the diet drinks aren’t causing your weight gain – increasing caloric intake is, perhaps coupled with a slowing metabolism.

Another theory on diet soda and weight gain is the scenario familiar to many dieters: it’s “okay” to eat that hot fudge sundae or that pack of fries, as long as we drink a diet pop. It’s important to remember that diet drinks don’t give us permission to load up on calories from other food and drink sources.

Can Diet Soda Trick Your Appetite?

Perhaps the most intriguing theory of how diet soda and weight gain interact is biological. When we drink diet soda and taste its sweetness, our bodies get the message that sweet, high-calorie foods are coming. However, when zero calories follow that good, sweet taste, the body is confused: where’s the promised good stuff? This may stimulate your hunger for other high-calorie foods and drinks, which may in turn lead to weight gain. In short, you can’t fool your body.

Does diet soda lead to weight gain? Hard to say definitively, but the evidence clearly suggests that zero-calorie drinks are no panacea for the dieter. Better to stick to no- and low-calorie flavored waters and iced teas for that flavor you’re craving while you diet.


About Author

Posts By content
  • moonlitfatty76

    I’m a diet coke lover and have been for years. But I have to have it with ice which is why I only drink the big fountain drinks. Over the past 3 years I have gained about 30 pounds. I thought back to when I started gaining weight and have linked it to me drinking a giant diet coke every morning and then another one at lunch time. Sometimes even more. This has been every day. So after reading similar articles like this one, I’ve almost finished my 2nd week without diet coke. I’m sticking to iced teas and water I guess. I’m also doing more exercising. So we’ll see if there’s a noticable difference hopefully soon.