Every study we read on this question

Trials in people (6)

• 1-week trial in 9 Japanese men: more weight gained on ultra-processed meals
  Randomized trial20249 peoplePoints to harm
• Trial in 350 pregnant women: food counselling did not clearly change birth weight
  Randomized trial2024256 peopleNo difference
• Trial in 20 adults checking whether diet order mattered for ultra-processed food results
  Randomized trial202420 peopleNo direction
• Trial in 50 adults: hard-texture meals cut intake by 21% of food weight
  Trial, not randomized202250 peopleMixed
• Trial in 20 adults: more calories eaten and weight gained on ultra-processed diet
  Randomized trial201920 peoplePoints to harm
• Trial in 34 adults: waist fell in both groups, gut bacteria differed
  Randomized trial202534 peopleMixed

Population studies (17)

• Survey of 326 Brazilians with diabetes: processed food linked to cholesterol, not blood sugar
  Population study: one-time survey2025326 peopleMixed
• Study of 2,217 Canadian children: ultra-processed food linked to overweight in boys, not girls
  Population study: followed a group20252,217 peoplePoints to harm
• In 114,064 health workers followed 30 years, ready-to-eat meats went with higher death risk
  Population study: followed a group2024114,064 peoplePoints to harm
• Study that followed 5,957 US adults: ultra-processed food linked to new high blood pressure
  Population study: followed a group20245,957 peoplePoints to harm
• Study of 595 children: ultra-processed food linked to larger body size at some ages
  Population study: followed a group2023595 peoplePoints to harm
• Study of 96 children with obesity: more ultra-processed food linked to higher blood pressure
  Population study: followed a group202396 peoplePoints to harm
• Study of 305 Brazilian children: ultra-processed food linked to higher blood pressure
  Population study: followed a group2023305 peoplePoints to harm
• Study that followed 198,636 adults: ultra-processed food linked to higher type 2 diabetes risk
  Population study: followed a group2023198,636 peoplePoints to harm
• Study that followed 142,052 US health workers: ultra-processed food linked to more bowel polyps
  Population study: followed a group2023142,052 peoplePoints to harm
• Study of 450,111 adults: swapping to less processed food linked to lower cancer risk
  Population study: followed a group2023450,111 peoplePoints to harm
• Study that followed 22,659 UK adults: ultra-processed food linked to higher obesity risk
  Population study: followed a group202122,659 peoplePoints to harm
• Study that followed 3,003 US adults: ultra-processed food linked to higher heart disease risk
  Population study: followed a group20213,003 peoplePoints to harm
• Study that followed 21,730 UK adults: ultra-processed food linked to more type 2 diabetes
  Population study: followed a group202121,730 peoplePoints to harm
• Study that followed 105,159 French adults: ultra-processed food linked to higher heart disease risk
  Population study: followed a group2019105,159 peoplePoints to harm
• Study that followed 19,899 Spanish graduates: ultra-processed food linked to higher death risk
  Population study: followed a group201919,899 peoplePoints to harm
• Study that followed 104,980 French adults: ultra-processed food linked to higher cancer risk
  Population study: followed a group2018104,980 peoplePoints to harm
• Survey of 30,243 Brazilians: ultra-processed food linked to higher odds of obesity
  Population study: one-time survey201530,243 peoplePoints to harm

Reviews (10)

• Review of 16 reviews: moderate-certainty link between ultra-processed food and death, heart disease, diabetes
  Systematic review2025Points to harm
• Review of 45 pooled analyses: ultra-processed food linked to 71% of health measures
  Systematic review20249,888,373 peoplePoints to harm
• Pooled review adding 122 new articles: ultra-processed food linked to 25 health outcomes
  Pooled review (meta-analysis)2024Points to harm
• Pooled review of 5 studies: ultra-processed food linked to some gut cancers
  Pooled review (meta-analysis)20241,128,243 peoplePoints to harm
• Pooled review of 11 studies: ultra-processed food linked to higher cancer risk
  Pooled review (meta-analysis)2023Points to harm
• Review of 17 long-term studies in adults: ultra-processed food linked to later obesity
  Systematic review2023Points to harm
• Review of 10 youth studies: four long ones linked ultra-processed food to obesity
  Systematic review2022Points to harm
• Review of 63 studies: ultra-processed food linked to obesity, heart disease, diabetes and cancer
  Systematic review2022Points to harm
• Review of studies: ultra-processed food linked to obesity, though firm conclusions were hard
  Systematic review2021Points to harm
• Pooled review of 23 studies: highest ultra-processed food intake linked to higher death risk
  Pooled review (meta-analysis)2021183,491 peoplePoints to harm

Opinion (5)

• Review of studies in young people: ultra-processed food linked to obesity and heart risk
  Opinion or narrative review2024Points to harm
• Review for general readers on why ultra-processed foods may harm health
  Opinion or narrative review2024Points to harm
• Review of 17 studies in adults: more ultra-processed food went with more obesity
  Opinion or narrative review2023Points to harm
• Review of how ultra-processed food might harm the heart
  Opinion or narrative review2021Points to harm
• Review of 9 studies: ultra-processed food went with overweight and obesity
  Opinion or narrative review2017Points to harm