Staff Profile

I am interested in research synthesis (combining scientific information to inform policy). My research focuses on applying evidence-based methods to trans-disciplinary problems relating to sustainable development and food security. I also work on specific applications in healthcare, environmental and social science domains. Methodological work focuses on validating existing methods and developing new techniques for evidence synthesis (by means of systematic review and meta-analysis), and evidence contextualization (by means of decision and systems analysis). I collaborate with others to disseminate the methodologies of evidence-based practice across disciplines reflecting a belief in generic methods for evidence-based x (EBX). I hate p values and am a passionate advocate of both meta-analysis and open science.

I believe that the best science is done in a transparent non hierarchical manner with an emphasis on team-work. I hate the toxic and coercive interactions that are a feature of broken academia. Please be respectful of both my expertise and feelings in any professional interactions.

 Outside of research synthesis, I enjoy fell/ultra running, underground exploration, gardening (particularly dwarf rhododendrons, arctic-alpines, and vegetables), fly fishing and drinking beer and whisky. I am also busy as a Dad and husband.

My >200 publications are listed on google scholar and the majority are available on research gate.

I am the quantitative methods lead on the Metius project: https://www.ukri.org/news/ai-investment-to-transform-global-policy-with-scientific-evidence/

UK Research and Innovation (UKRI) has announced funding for a landmark investment to revolutionise how scientific evidence and research is synthesised and delivered to policymakers in the UK and worldwide.

Mobilising evidence through artificial intelligence (AI) and user-informed synthesis (METIUS) is a new infrastructure.

It aims to harness cutting-edge AI to dramatically improve the speed, relevance and accessibility of evidence synthesis for decision-makers tackling urgent challenges.

Science Minister, Lord Vallance, said:

The challenge for policymakers is often in sourcing the specific information they need from troves of research, rather than a lack of available evidence.

This UK-led project will use AI to pinpoint the information researchers need, and quickly, to improve outcomes in everything from education to justice, climate change to international development, which ultimately benefits us all.

Strengthen the UK’s position in research

Stian Westlake, Economic and Social Research Council (ESRC) Executive Chair, said:

AI has enormous potential to turn a mass of diffuse research into synthesised, useful summaries, which can help policy makers and practitioners deliver better outcomes for citizens.

This new infrastructure investment has the potential to transform how evidence informs policy decisions, and strengthen the UK’s position as a leader in research and innovation, driving economic growth and improving lives.

METIUS is funded by UKRI through ESRC and the Natural Environment Research Council (NERC) with co-funding from the Department for Science, Innovation and Technology (DSIT).

• Articles

  • Robinson AD, Cartigny S, Stewart G, Bishop BA, Robbins LJ, Flynn SL. Use of near-surface waters in identifying elemental associations with geothermal-sourced Li. Applied Geochemistry 2025, 188, 106428.
  • O'Connell NE, Belton J, Crombez G, Eccleston C, Fisher E, Ferraro MC, Hood A, Keefe F, Knaggs R, Norris E, Palermo TM, Pickering G, Pogatzki-Zahn E, Rice AS, Richards G, Segelcke D, Smart KM, Soliman N, Stewart G, Tolle T, Turk D, Vollert J, Wainwright E, Wilkinson J, Williams ACDC. Enhancing the trustworthiness of pain research: A call to action. Journal of Pain 2025, 28, 104736.
  • Robinson AD, Acikalin S, Stewart G, Bishop B, Robbins LJ, Flynn S. Understanding the Li resource of granite hosted geothermal brines using near surface measurements. EarthArXiv 2024. Submitted.
  • Boyd RJ, Stewart GB, Pescott OL. Descriptive inference using large, unrepresentative nonprobability samples: An introduction for ecologists. Ecology 2024, 105(2), e4214.
  • Aloe AM, Dewidar O, Hennessy EA, Pigott T, Stewart G, Welch V, Wilson DB, Campbell MECCIR Working Group. Campbell Standards: Modernizing Campbell's Methodologic Expectations for Campbell Collaboration Intervention Reviews (MECCIR). Campbell Systematic Reviews 2024, 20(4), e1445.
  • O'Connell N, Moore RA, Stewart G, Fisher E, Hearn L, Eccleston C, Wewege M, De C Williams AC. Trials We Cannot Trust: Investigating Their Impact on Systematic Reviews and Clinical Guidelines in Spinal Pain. Journal of Pain 2023, 24(12), 2103-2130.
  • Marikyan D, Papagiannidis S, Stewart G. Technology acceptance research: Meta-analysis. Journal of Information Science 2023, Epub ahead of print.
  • Carrick J, Bell D, Fitzsimmons C, Gray T, Stewart G. Principles and practical criteria for effective participatory environmental planning and decision-making. Journal of Environmental Planning and Management 2023, 66(14), 2854-2877.
  • Pescott OL, Stewart GB. Simulation-based study design accuracy weights are not generalisable and can still lead to biased meta-analytic inference: Comments on Christie et al. (2019). Journal of Applied Ecology 2022, 59(5), 1187-1190.
  • Boyd RJ, Powney GD, Burns F, Danet A, Duchenne F, Grainger MJ, Jarvis SG, Martin G, Nilsen EB, Porcher E, Stewart GB, Wilson OJ, Pescott OL. ROBITT: A tool for assessing the risk-of-bias in studies of temporal trends in ecology. Methods in Ecology and Evolution 2022, 13(7), 1497-1507.
  • Sharma Waddington H, Wilson DB, Pigott T, Stewart G, Aloe AM, Tugwell P, Welch V. Quasi-experiments are a valuable source of evidence about effects of interventions, programs and policies: commentary from the Campbell Collaboration Study Design and Bias Assessment Working Group. Journal of Clinical Epidemiology 2022, 152, 311-313.
  • Reed MS, Young DM, Taylor NG, Andersen R, Bell NGA, Cadillo-Quiroz H, Grainger M, Heinemeyer A, Hergoualc'h K, Gerrand AM, Kieft J, Krisnawati H, Lilleskov EA, Lopez-Gonzalez G, Melling L, Rudman H, Sjogersten S, Walker JS, Stewart G. Peatland core domain sets: building consensus on what should be measured in research and monitoring. Mires and Peat 2022, 28, 26.
  • Piras S, Righi S, Setti M, Koseoglu N, Grainger MJ, Stewart GB, Vittuari M. From social interactions to private environmental behaviours: The case of consumer food waste. Resources, Conservation and Recycling 2022, 176, 105952.
  • Iqbal WA, Stewart GB, Smith A, Errington L, Seal CJ. PROTOCOL: The association between whole‐grain dietary intake and noncommunicable diseases: A systematic review and meta‐analysis. Campbell Systematic Reviews 2021, 17(3), e1186.
  • Whittingham MJ, McKenzie AJ, Francksen RM, Feige D, Cadwallender T, Grainger M, Fazaa N, Rhymer C, Wilkinson C, Lloyd P, Smurthwaite B, Percival SM, Morris-Hale T, Rawcliffe C, Dewson C, Woods S, Stewart GB, Oughton E. Offshore refuges support higher densities and show slower population declines of wintering Ruddy Turnstones Arenaria interpres: a response. Bird Study 2020, 67(2), 264-267.
  • Grainger MJ, Bolam FC, Stewart GB, Nilsen EB. Evidence synthesis for tackling research waste. Nature Ecology & Evolution 2020, 4, 495-497.
  • Bolam FC, Grainger MJ, Mengersen KL, Stewart GB, Sutherland WJ, Runge MC, McGowan PJK. Using the Value of Information to improve conservation decision making. Biological Reviews 2019, 94(2), 629-647.
  • Whittingham MJ, McKenzie AJ, Francksen RM, Feige D, Cadwallender T, Grainger M, Fazaa N, Rhymer C, Wilkinson C, Lloyd P, Smurthwaite B, Percival SM, Morris-Hale T, Rawcliffe C, Dewson C, Woods S, Stewart GB, Oughton E. Offshore refuges support higher densities and show slower population declines of wintering Ruddy Turnstones Arenaria interpres. Bird Study 2019, 66(4), 431-440.
  • Carrick J, Abdul Rahim MSAB, Adjei C, Ashraa Kalee HHH, Banks SJ, Bolam FC, Campos Luna IM, Clark B, Cowton J, Domingos IFN, Golicha DD, Gupta G, Grainger M, Hasanaliyeva G, Hodgson DJ, Lopez-Capel E, Magistrali AJ, Merrell IG, Oikeh I, Othman MS, Ranathunga Mudiyanselage TKR, Samuel CWC, Sufar EKH, Watson PA, Zakaria NNAB, Stewart G. Is planting trees the solution to reducing flood risks?. Journal of Flood Risk Management 2019, 12(S2), e12484.
  • Clark B, Panzone LA, Stewart GB, Kyriazakis I, Niemi JK, Latvala T, Tranter R, Jones P, Frewer LJ. Consumer attitudes towards production diseases in intensive production systems. PLOS One 2019, 14(1), e0210432.
  • McGowan PJG, Stewart GB, Long G, Grainger MJ. An imperfect vision of indivisibility in the Sustainable Development Goals. Nature Sustainability 2019, 2, 43-45.
  • Stavrakakis S, Loisel F, Sakkas P, Le Floc'H N, Kyriazakis I, Stewart G, Montagne L. A systematic literature mapping and meta-analysis of animal-based traits as indicators of production diseases in pigs. Animal 2019, 13(7), 1508-1518.
  • Grainger MJ, Aramyan L, Logatchevac K, Piras S, Righi S, Settib M, Vittuari M, Stewart GB. The use of systems models to identify food waste drivers. Global Food Security 2018, 16, 1-8.
  • Grainger MJ, Aramyan L, Piras S, Quested TE, Righi S, Setti M, Vittuari M, Stewart GB. Model selection and averaging in the assessment of the drivers of household food waste to reduce the probability of false positives. PLOS one 2018, 13(2), e0192075.
  • Gurevitch J, Koricheva J, Nakagawa S, Stewart G. Meta-analysis and the science of research synthesis. Nature 2018, 555, 175-182.
  • Kendall H, Kaptan G, Stewart G, Grainger M, Kuznesof S, Naughton P, Clark B, Hubbard C, Raley M, Marvin HJP, Frewer LJ. Drivers of existing and emerging food safety risks: Expert opinion regarding multiple impacts. Food Control 2018, 90, 440-458.
  • Clark B, Frewer LJ, Panzone L, Stewart G. The need for formal policy synthesis in food policy. A case study of willingness to pay. Animals 2017, 7(3), 23.
  • Grainger MJ, Stewart GB. The jury is still out on social media as a tool for reducing food waste a response to Young et al. (2017). Resources, Conservation and Recycling 2017, 122, 407-410.
  • Hudson JA, Frewer LJ, Jones G, Brereton PA, Whittingham MJ, Stewart G. The Agri-food chain and Antimicrobial Resistance: a review. Trends in Food Science & Technology 2017, 69(Part A), 131-147.
  • Stephenson F, Mill AC, Scott C, Stewart GB, Grainger MJ, Polunin NVC, Fitzsimmons C. Socio-economic, technological and environmental drivers of spatio-temporal changes in fishing pressure. Marine Policy 2017, 88, 189-203.
  • Clark B, Stewart G, Panzone L, Kyriazakis I, Frewer LJ. Citizens, consumers and farm animal welfare: A meta-analysis of willingness-to-pay studies. Food Policy 2017, 68, 112-127.
  • Cooper J, Baranski M, Stewart G, Nobel-de Lange M, Bàrberi P, Fließbach A, Peigné J, Berner A, Brock C, Casagrande M, Crowley O, David C, De Vliegher A, Döring TF, Dupont A, Entz M, Gorsse M, Haase T, Halde C, Hammerl V, Huiting H, Leithold G, Messmer M, Schloter M, Sukkel W, van der Heijgen MGA, Willekens K, Wittwer R, Mäder P. Shallow non-inversion tillage in organic farming maintains crop yields and increases soil C stocks: a meta-analysis. Agronomy for Sustainable Development 2016, 36(1), 22.
  • Whaley P, Halsall CJ, Ågerstrand M, Aiassa E, Benford D, Bilotta G, Coggon D, Collins C, Dempsey C, Duarte-Davidson R, FitzGerald R, Galay-Burgos M, Gee D, Hoffmann S, Lam J, Lasserson T, Levy L, Lipworth S, Mackenzie Ross S, Martin O, Meads C, Meyer-Baron M, Miller J, Pease C, Rooney A, Sapiets A, Stewart GB, Taylor D. Implementing systematic reviews techniques in chemical risk assessment: Challenges, opportunities and recommendations. Environment International 2016, 92-93, 556-564.
  • Srednicka-Tober D, Baranski M, Seal CJ, Sanderson R, Benbrook C, Steinshamn H, Gromadzka-Ostrowska J, Rembialkowska E, Skwarlo-Sonta K, Eyre M, Cozzi G, Larsen MK, Jordon T, Niggli U, Sakowski T, Calder PC, Burdge GC, Sotiraki S, Stefanakis A, Stergiadis S, Yolcu H, Chatzidimitriou E, Butler G, Stewart G, Leifert C. Higher PUFA and n-3 PUFA, conjugated linoleic acid, α-tocopherol and iron, but lower iodine and selenium concentrations in organic milk: a systematic literature review and meta- and redundancy analyses. British Journal of Nutrition 2016, 115(6), 1043-1060.
  • Srednicka-Tober D, Baranski M, Seal CJ, Sanderson R, Benbrook C, Steinshamn H, Gromadzka-Ostrowska J, Rembialkowska E, Skwarlo-Sonta K, Eyre M, Cozzi G, Larsen MK, Jordon T, Niggli U, Sakowski T, Calder PC, Burdge GC, Sotiraki S, Stefanakis A, Yolcu H, Stergiadis S, Chatzidimitriou E, Butler G, Stewart G, Leifert C. Composition differences between organic and conventional meat: a systematic literature review and meta-analysis. British Journal of Nutrition 2016, 115(6), 994-1011.
  • Clark B, Stewart GB, Panzone LA, Kyriazakis I, Frewer LJ. A systematic review of public attitudes, perceptions and behaviours towards production diseases associated with farm animal welfare. Journal of Agricultural and Environmental Ethics 2016, 29(3), 455-478.
  • Llewellyn A, Whittington C, Stewart G, Higgins JPT, Meader N. The use of Bayesian networks to assess the quality of evidence from research synthesis: 2. Inter-rater reliability and Comparison with standard GRADE assessment. PLoS ONE 2015, 10(12), e0123511.
  • Stewart GB, Higgins JPT, Schunemann H, Meader N. The Use of Bayesian Networks to Assess the Quality of Evidence from Research Synthesis: 1. PLoS One 2015, 10(4).
  • Lortie CJ, Stewart GB, Rothstein H, Lau J. How to critically read ecological meta-analyses. Research synthesis methods 2015, 6, 124-133. In Preparation.
  • Stewart GB, Meader N, Mengersen K. Potential uses of Bayesian networks as tools for synthesis of systematic reviews of complex interventions. Research Synthesis Methods 2014, 5(1), 1-12.
  • Pescott OL, Stewart GB. Assessing the impact of human trampling on vegetation: a systematic review and meta-analysis of experimental evidence. PeerJ 2014, 2, e360.
  • Clark B, Stewart GB, Panzone LA, Frewer LJ. A protocol for a systematic review into consumers' attitudes, beliefs and perceived ethical obligations towards farm animal welfare. PeerJ 2014.
  • Clark B, Stewart GB, Panzone LA, Frewer LJ. A Protocol for a meta-analysis of consumers' and citizens willingness-to-pay for farm animal welfare and disease prevention. PeerJ PrePrints 2014.
  • Meader N, King K, Llewellyn A, Norman G, Brown J, Rodgers M, Moe-Byrne T, Sowden A, Stewart GB. A checklist designed to aid consistency and reproducibility of GRADE assessments: development and pilot validation. Systematic Reviews 2014, 3, 82.

• Conference Proceedings (inc. Abstracts)

  • Warner S, Seal C, Haldar S, Stewart G, Brandt K. A project to investigate the effects of carrot and other polyacetylene-rich vegetable consumption on biomarkers of chronic disease risk. In: International Symposium on Carrot and Other Apiaceae. 2017, Angers, France: International Society for Horticultural Science.
  • Bieber A, Stergiadis S, Franceschin E, Isensee A, Eyre MD, Maurer V, Chatzidimitriou E, Cozzi G, Bapst B, Stewart G, Gordon A, Butler G, Leifert C. Influence of US Brown Swiss genetics and grazing on bovine milk fatty acid profile. In: Proceedings of the Swiss Association for Animal production Annual Conference (in German). 2015.
  • Bieber A, Stergiadis S, Franceschin E, Isensee A, Eyre MD, Maurer V, Chatzidimitriou E, Cozzi G, Bapst B, Stewart G, Gordon A, Butler G, Leifert C. Influence of Brown Swiss genetics and grazing on the fatty acid composition of cow's milk in low-input systems. In: Healthy and productive animals: should we adapt the genotype to the feed or vis versa? ETH Series for Animal Nutrition (in German). 2015.
  • Srednicka-Tober D, Baranski M, Seal C, Sanderson R, Stewart G, Benbrook C, Rembialkovska E, Niggli U, Volakakis N, Leifert C. Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses. In: 12th European Nutrition Conference (FENS). 2015, Berlin, Germany: Karger.
  • Bieber A, Stergiadis S, Franceschin E, Isensee A, Eyre MD, Maurer V, Chatzidimitriou E, Cozzi G, Bapst GB, Stewart G, Gordon A, Butler G, Leifert C. Einfluss von Brown Swiss Genetik und Weidegang auf die Fettsäurezusammensetzung von Kuhmilch. In: Swiss Association for Animal Production. 2015, Zollikofen, Switzerland: HAFL.
  • Stergiadis S, Bieber A, Francheschin E, Isensee A, Eyre MD, Maurer V, Chatzidimitriou E, Cozzi G, Bapst B, Stewart G, Gordon A, Butler G, Leifert C. Crossbreeding low-input dairy cows in Switzerland with US Brown Swiss: effect on summer milk fatty acid profile. In: British Society of Animal Science Annual Conference. 2015, Chester, UK: Cambridge University Press.

• Editorial

  • Stewart GB, Schmid CH. Lessons from meta-analysis in ecology and evolution: the need for trans-disciplinary evidence synthesis methodologies. Research Synthesis Methods 2015, 6(2), 109-110.

• Letters

  • O'Connell NE, Moore RA, Stewart G, Fisher E, Hearn L, Eccleston C, Williams ACDC. Reply to Monticone. Pain 2023, 164(4), E239-E241.
  • Williams ACDC, Hearn L, Moore RA, Stewart G, Fisher E, Eccleston C, O'Connell NE. Effective quality control in the medical literature: investigation and retraction vs inaction. Journal of Clinical Epidemiology 2023, 157, 156-157.
  • Bayliss HR, Lortie CJ, Stewart GB. How "good" is half a fish? Communicating outcomes of quantitative syntheses to decision makers. Frontiers in Ecology and the Environment 2015, 13(10), 533-534.

• Notes

  • Piras S, Righi S, Setti M, Koseoglu N, Grainger MJ, Stewart GB, Vittuari M. Corrigendum to ‘From social interactions to private environmental behaviours: The case of consumer food waste’, Resources, Conservation and Recycling 176 (2022), 105952. Resources, Conservation and Recycling 2022, 178, 106019.
  • Stewart G, Ward J. Meta-science urgently needed across the environmental nexus: a comment on Berger-Tal et al. Behavioral Ecology 2019, 30(1), 9-10.
  • Cook CN, Pullin AS, Sutherland WJ, Stewart GB, Carrasco LR. Considering cost alongside the effectiveness of management in evidence-based conservation: A systematic reporting protocol. Biological Conservation 2017, 209, 508-516.

• Reports

  • Stewart GB, Glendell M, McMorran R, Troldborg M, Gagkas Z, Ovando P, Roberts M, Maynard C, Williams A, Clay G, Reed MS. Uplandia: making better policy in complex upland systems. Final Report. Defra and Natural England, 2021.
  • Reed MS, Kenter JO, Hansda R, Martin J, Curtis T, Prior S, Hay M, Saxby H, Mills L, Post J, Garrod G, Proctor A, Collins O, Guy JA, Stewart G, Whittingham M. Social barriers and opportunities to the implementation of the England Peat Strategy : Final report. Newcastle upon Tyne: Natural England and Defra, Newcastle University, 2020.

• Reviews

  • Francksen RM, Turnbull S, Rhymer CM, Hiron M, Bufe C, Klaus VH, Newell-Price P, Stewart G, Whittingham MJ. The Effects of Nitrogen Fertilisation on Plant Species Richness in European Permanent Grasslands: A Systematic Review and Meta-Analysis. Agronomy 2022, 12(12), 2928.
  • Haddaway NR, Bethel A, Dicks LV, Koricheva J, Macura B, Petrokofsky G, Pullin AS, Savilaakso S, Stewart GB. Eight problems with literature reviews and how to fix them. Nature Ecology and Evolution 2020, 4, 1582–1589.
  • Stewart LA, Clarke M, Rovers M, Riley RD, Simmonds M, Stewart G, Tierney JF, PRISMA-IPD Dev Grp. Preferred Reporting Items for a Systematic Review and Meta-analysis of Individual Participant Data The PRISMA-IPD Statement. JAMA-Journal of the American Medical Association 2015, 313(16), 1657-1665.
  • Simmonds M, Stewart G, Stewart L. A decade of individual participant data meta-analyses: A review of current practice. Contemporary Clinical Trials 2015, 45(Part A), 76-83.
  • Baranski M, Srednicka-Tober D, Volakakis N, Seal C, Sanderson R, Stewart GB, Benbrook C, Biavati B, Markellou E, Giotis C, Gromadzka-Ostrowska J, Rembialkowska E, Skwarlo-Sonta K, Tahvonen R, Janovska D, Niggli U, Nicot P, Leifert C. Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses. British Journal of Nutrition 2014, 112(5), 794-811.