First, let's define 'diet soda' as any drink that is sweetened with low to no calorie sweeteners (like sucralose, aspartame, acesulfame-potassium, etc.) in order to taste like regular (sugared) soda.
In short, there are no direct causative studies that show the use of artificial sweeteners slows your metabolism or promotes fat storage.
The CHOICE randomized study, lasting 6 months and observing how different diet changes affect weight loss adherence, found that diet soda is an effective substitution for regular soda and had no significant differences in health or weight loss relative to water.
Data from the NHANES (03-04) study suggest that increased servings of non-caloric beverages are not related to an increase in total calories. Additionally, the PREMIER trial found that a reduction in intake of non-caloric beverage is not associated with weight loss.
The real problem is that people tend to under-estimate caloric intake. By thinking about the zero calories in the soda, they end up eating an excess of calories, thus increasing fat storage. This makes the well known correlation (relationship) between diet soda and obesity; one does not cause the other, but they tend to co-exist. Drinking diet soda does not make one fat, but people with obesity tend to drink diet soda.
In regards to insulin, diet soda can potentially increase insulin secretion by both an anticipatory response and the artificial sweetener aspartame can (through the amino acid, phenylalanine). However, both of these insulin spikes are too small to matter practically, and the latter mechanism doesn't seem to occur at all with many commonly ingested dosages.
As mentioned on our Aspartame and Appetite page, aspartame (via phenylalanine) might also suppress appetite.
33% OFF SALE ENDS TONIGHT: Supplement Guides — Actionable information to help you reliably improve your health.
Get precise instructions for your specific scenario
Avoid wasting hundreds of dollars on useless supplements
Reach your health goals with the right combo of supplementsSave 33% and Get started today »
- Does aspartame cause headaches?
- Do artificial sweeteners spike insulin?
- Does aspartame increase appetite?
- Does diet soda cause strokes and dementia?
- Is diet soda bad for you?
- Does Garcinia Cambogia help with weight loss?
- Can hypothyroidism lead to fat gain?
- How do I stay out of "starvation mode?"
- Measuring body fat percentage: It's an accuracy thing
- Does eating at night make it more likely to gain weight?
- How to minimize fat gain when you binge
- Be the tortoise or the hare: it doesn’t matter for fat loss
- A compound from beer may help fat loss
- Can one binge make you fat?
- Will carbs make me fat?
- How do I get a six-pack?
- How does protein affect weight loss?
- What should you eat for weight loss?
- Will lifting weights convert my fat into muscle?
- How do I lose fat around my belly?
- Does high-protein intake help when dieting?
- Does eating fat make you fat?
- How important is sleep?
- How to minimize fat gain during the holidays
- I have lost significant weight and now have loose skin. How can I tighten up my skin?
- Stepping up weight loss: Can walking help dieters shed fat?
- Is It Time to Sound the Alarm on Artificial Sweeteners?
- Artificial sweeteners - Is the evidence as sweet as these substitutes?
- Low-fat vs. low-carb? Major study concludes: it doesn’t matter for weight loss
- Is my “slow metabolism” stalling my weight loss?
- The lowdown on intermittent fasting
- I'm not too tired to stuff my face
- Will eating breakfast keep you lean?
- Do you need to detox?
- Can you lose weight by turning down the heater?
- Does daily weighing help you lose weight?
- Is it really that bad to skip breakfast?
- Will my breasts shrink with weight loss?
- Exploring chia seeds for weight loss
- Can food have negative calories?
- 5 little-known facts about protein
- 3 Science-based steps to curbing your appetite
- Whey vs soy protein: which is better when losing weight?
- Sucrose-sweetened beverages increase fat storage in the liver, muscle, and visceral fat depot: a 6-mo randomized intervention study. Am J Clin Nutr. (2011) Maersk M, et al.
- Replacing caloric beverages with water or diet beverages for weight loss in adults: main results of the Choose Healthy Options Consciously Everyday (CHOICE) randomized clinical trial. Am J Clin Nutr. (2012) Tate DF, et al.
- Impact of change in sweetened caloric beverage consumption on energy intake among children and adolescents. Arch Pediatr Adolesc Med. (2009) Wang YC, et al.
- Reduction in consumption of sugar-sweetened beverages is associated with weight loss: the PREMIER trial. Am J Clin Nutr. (2009) Chen L, et al.
- A Pavlovian approach to the problem of obesity. Int J Obes Relat Metab Disord. (2004) Davidson TL, Swithers SE.