Retraction and republication—Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial

Abstract

On June 6, 2016, The Lancet Diabetes & Endocrinology published online an analysis1Estruch R Martinez-Gonzalez MA Corella D et al.Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial.Lancet Diabetes Endocrinol. 2016; 4: 666-676Summary Full Text PDF PubMed Scopus (118) Google Scholar of secondary outcomes from the PREDIMED trial, examining the effects of a high-fat Mediterranean diet on bodyweight and waist circumference, and the Article was published in print in the August, 2016, issue of the journal. In June, 2017, concerns were raised2Carlisle JD Data fabrication and other reasons for non-random sampling in 5087 randomised, controlled trials in anaesthetic and general medical journals.Anaesthesia. 2017; 72: 944-952Crossref PubMed Scopus (113) Google Scholar about the implausibility of baseline data in the primary report of the PREDIMED trial,3Estruch R Ros E Salas-Salvadó J et al.Primary prevention of cardiovascular disease with a Mediterranean diet.N Engl J Med. 2013; 368: 1279-1290Crossref PubMed Scopus (3249) Google Scholar and on June 14, 2018, the primary report was retracted and republished with updated analyses that accounted for protocol deviations and departures from individual randomisation in a subsample of participants.4Estruch R Ros E Salas-Salvadó J et al.Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts.N Engl J Med. 2018; 378: e34Crossref PubMed Scopus (728) Google Scholar On June 14, 2018, the Editors of The Lancet Diabetes & Endocrinology contacted the authors to discuss whether and what corrections were required to their report of analyses of secondary outcomes,1Estruch R Martinez-Gonzalez MA Corella D et al.Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial.Lancet Diabetes Endocrinol. 2016; 4: 666-676Summary Full Text PDF PubMed Scopus (118) Google Scholar and published an Expression of Concern5The Editors of The Lancet Diabetes & EndocrinologyExpression of concern—Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial.Lancet Diabetes Endocrinol. 2018; 6: 763Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar to alert readers while these discussions were ongoing. In view of the extent of changes necessary, we determined that the previous version of the Article should be retracted and a corrected version republished after re-analysis and re-review, in accordance with the Committee on Publication Ethics guidelines. Today we retract the previous version and republish the corrected version of the Article6Estruch R Martinez-Gonzalez MA Corella D et al.Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial.Lancet Diabetes Endocrinol. 2019; 7: e6-e17Summary Full Text Full Text PDF PubMed Scopus (62) Google Scholar and appendix, in which the findings have changed slightly—eg, 5 year changes in bodyweight and waist circumference in the Mediterranean diet with olive oil group were no longer significant compared with the control group; 5 year changes in waist circumference in the Mediterranean diet with nuts group were still significant compared with the control group. The overall messages of the paper are similar. The updated version of the Article includes an appendix file annotating all changes made to the paper. We also publish a Correction to the linked Comment.7Mozaffarian D Food and weight gain: time to end our fear of fat.Lancet Diabetes Endocrinol. 2016; 5: 633-635Summary Full Text Full Text PDF Scopus (15) Google Scholar Retracted: Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trialA long-term intervention with an unrestricted-calorie, high-vegetable-fat Mediterranean diet was associated with decreases in bodyweight and less gain in central adiposity compared with a control diet. These results lend support to advice not restricting intake of healthy fats for bodyweight maintenance. Full-Text PDF Food and weight gain: time to end our fear of fatIn The Lancet Diabetes & Endocrinology, Ramon Estruch and colleagues1 report on long-term bodyweight change in PREDIMED, a multicentre trial in which 7447 men and women with type 2 diabetes or multiple cardiovascular risk factors were assigned to a control diet (advice to reduce dietary fat) or one of two Mediterranean diets including liberal intake of extra-virgin olive oil or nuts. After 5 years, dietary fat consumption was substantially higher in the Mediterranean diets than in the control diet (42% vs 37% energy), yet without greater weight gain, and actually some evidence for lower waist circumference in the group assigned to Mediterranean diet plus nuts. Full-Text PDF