Every study we read on this question

Trials in people (11)

• 12-week trial in 46 young people: diet drinks did not clearly change BMI
  Randomized trial202546 peopleNo difference
• 26-week trial in 101 adults found no clear weight difference with higher sweetener intake
  Trial, not randomized2020101 peopleNo difference
• 12-week trial in 123 adults: weight rose with sugar and saccharin, not other sweeteners
  Randomized trial2019123 peopleMixed
• 1-year trial in 303 adults: diet drinks kept off more weight than water
  Randomized trial2016303 peoplePoints to benefit
• 24-week trial in 179 adults with diabetes: diet drinks beat water for blood sugar
  Randomized trial2026179 peoplePoints to benefit
• 4-week trial in 59 adults found no clear gut bacteria difference, stevia versus sugar
  Randomized trial202459 peopleNo difference
• 4-week trial in 42 women: sweeteners did not clearly change blood sugar or weight
  Randomized trial202342 peopleNo difference
• 10-day trial in healthy adults: sucralose with a carbohydrate lowered insulin sensitivity
  Trial, not randomized2020Points to harm
• 2-week trial in 17 adults: aspartame or sucralose did not clearly change blood sugar
  Randomized trial202017 peopleNo difference
• Trial in 21 adults: swallowed sucralose raised blood sugar; insulin effects differed by weight
  Randomized trial201921 peopleMixed
• Trial in 30 healthy men: sweetener drinks did not clearly change daily food intake
  Randomized trial201730 peopleNo difference

Population studies (5)

• Study that followed 143,409 adults: sugary-to-diet swaps went with less weight gain
  Population study: followed a group2026143,409 peoplePoints to benefit
• Study that followed 36,608 Australians: diet drinks linked to higher type 2 diabetes risk
  Population study: followed a group202536,608 peoplePoints to harm
• Survey of 351,805 UK adults: sweetener in coffee linked to metabolic syndrome
  Population study: one-time survey2024351,805 peoplePoints to harm
• Survey of 892 South Asian adults: sweetener use linked to more body fat
  Population study: one-time survey2018892 peoplePoints to harm
• Study that followed 1,454 adults: sweetener use linked to higher BMI and bigger waists
  Population study: followed a group20161,454 peoplePoints to harm

Blood and genes (1)

• Study of 500 Dutch children: urine saccharin and sucralose linked to higher BMI score
  Blood level study2025500 peoplePoints to harm

Reviews (10)

• Pooled review of 12 studies in young people found mixed results on diet drinks
  Pooled review (meta-analysis)2024Mixed
• Pooled review of 19 studies: sweeteners linked to preterm birth, not pregnancy weight gain
  Pooled review (meta-analysis)2024203,706 peopleMixed
• Review of 55 studies: diet drinks linked to higher obesity and diabetes risk
  Systematic review2023Points to harm
• Pooled review of 6 studies linked sweeteners in pregnancy to higher baby BMI score
  Pooled review (meta-analysis)2022Points to harm
• Review of sweeteners, fatty liver and insulin resistance raised concerns about artificial ones
  Systematic review2020Points to harm
• Pooled review of 56 studies of sweeteners in adults and children found mixed results
  Pooled review (meta-analysis)2019Mixed
• Pooled review of 29 trials found sweeteners did not clearly change blood sugar
  Pooled review (meta-analysis)2018741 peopleNo difference
• Pooled review of 37 studies found mixed results on sweeteners and BMI
  Pooled review (meta-analysis)2017Mixed
• Pooled review of 3 studies: diet soda drinkers linked to higher obesity risk
  Pooled review (meta-analysis)2017Points to harm
• Review of 372 human studies found no clear evidence of weight benefit or harm
  Systematic review2017No difference

Opinion (5)

• Review of how aspartame may affect weight, with the long-term obesity link still debated
  Opinion or narrative review2026Points to harm
• Review of sweeteners, blood sugar, gut bacteria and weight found mixed results
  Opinion or narrative review2022Mixed
• Review of low-calorie sweeteners and weight in children and teens found mixed results
  Opinion or narrative review2019Mixed
• Review of animal and long-term human studies: sweeteners may add to obesity risk
  Opinion or narrative review2016Points to harm
• Review of animal and human studies: sweeteners linked to weight gain and obesity
  Opinion or narrative review2016Points to harm