For many people, the indulgence of a sweet diet soda is a guilt-free pleasure, and it's considered a savior for just about anyone trying to lose weight. Does diet soda really have zero consequences when it comes to weight gain, though?
To get to the bottom of how diet soda affects weight, we sought out expert advice from a doctor and registered dietitian. First, however, it's important to be clear on what diet soda actually is because there are so many different drinks out there. Diet sodas are calorie-free or close to it. Usually the sweetness from sugar is replaced with sweeteners that are calorie-free. The question is whether or not replacing calorie-dense sugar with a calorie-free alternative will still make you gain weight.
The age-old mantra of weight control has always been calories in versus calories out, or in other words, if your body burns more calories than you consume, you'll lose weight. This leads most of us to think that diet soda is harmless toward weight gain because it doesn't add to your calorie intake. The truth, however, is more complex than this simple math equation. After all, most things that seem too good to be true usually are. Let's see if diet soda falls into that category.
A Doctor's Take on Diet Soda
"The zero calories from diet soda don't necessarily mean zero weight gain. There's been a lot of research that suggested diet soda alters your perception of sugar. So that even if you don't get the calories from that diet soda, you may end up drinking and eating more calories from other sources," said Jonathan Fricke MD, MHP.
What this means is that the more often you consume foods or drinks that taste sweet, like diet soda, the less sensitive your body becomes to sweet foods. It's similar to how the more coffee you drink the more you need to have the same effect, which could mean your body will crave more sugar than ever before if you favor diet drinks.
And we may not be able to fully trust science on this one, as all the studies and research making claims about diet soda and weight gain probably aren't totally reliable yet. "A lot of the research comes from rats and mice so it may not translate to human beings," Dr. Fricke warned. Last time we checked, a mouse and a human are pretty different.
The doctor's final word on diet soda? "The mantra of everything in moderation is the important bottom line for it," Dr. Fricke cautioned. "I recommend to my patients there's no reason from a health perspective to drink anything other than water."
A Dietician's Take on Diet Soda
The research on diet soda is still growing and not completely conclusive, as McKenzie Flinchum RD, LD/N, CPT and owner of Flexible Dietetics LLC pointed out.
According to Flinchum, "There are studies on the possible increase of sugar cravings with intake of diet soda, as well as studies revealing that artificial sweeteners may not activate the food-reward pathways in the brain. Other factors would need to take place to link diet soda to weight gain, but from what is currently known, diet soda contains alternative sweeteners, which contain zero calories, thus not contributing to overall caloric intake."
What does all this mean to you? Basically, not adding calories to your diet by drinking diet soda won't mean putting on a few extra pounds — at least in the short term. The long-term effects on how it could change your body are still unclear. Constantly having a sweet drink that doesn't have the same impact on the body as sugar could distort your perception of sugar and sweetness, leading you to overindulge down the road. Drinking a diet soda may mean no calories today, but it could lead you to reach for an extra bar of chocolate or slice of cake later.
Flinchum's overall recommendation? "I would recommend decreasing overall soda intake, regardless of whether it is diet or not, and switching to either more water or a better drink option than soda. In moderation, diet soda can be enjoyed as part of a healthy lifestyle. In certain cases, it may aid in weight loss. But as with anything, moderation is key."
Final Word on Diet Soda
In the short term, drinking diet soda won't lead to weight gain because you won't be consuming any extra calories. It's especially true if you're used to drinking regular soda and make the switch. The biggest factor to consider will be how consuming a sweet beverage affects the body and your sense of sweetness. It may turn out that the effects are minimal or they may end up being substantial enough to desensitize how satisfying sweet foods taste, which could lead to overindulgence. For now, it seems safe to say that diet soda doesn't lead to any immediate weight gain, but if it's all you drink, it may usher in some unwanted pounds in the future.