My interests are in both nutrition epidemiology and clinical nutrition.

Epidemiological projects include analysis of the association of diet with non-communicable diseases such as cardiovascular disease, cancer, obesity and diabetes, but also neurodegenerative diseases. I have led the nutrition part of HUSK3 (Hordaland Health Studies 2018-2021, see https://husk.w.uib.no/. In HUSK, we are investigating the association of dietary factors with weight changes, muscle health, and risk for diabetes, Parkinson's disease and mortality. We also investigate diet and risk of Parkinson's disease in the European EPIC cohort, in collaboration with DKFZ Heidelberg in Germany (https://www.dkfz.de/epidemiologie-von-krebserkrankungen/epic) and as PI in the KG Jebsen centre for Parkinson's disease (https://www.uib.no/en/parkinsonsdisease).

Furthermore, I am interested in causes and consequences of disease-related malnutrition.

We conduct high quality clinical studies with foods, ingredients and nutrients. We are particularly interested in the health effects of bread, whole grains and dietary fiber, and have conducted a number of studies with bread, beta-glucan and other types of dietary fiber. We received support from the EU for an international research project on whole grain and beta-glucan (Carbhealth, https://www.healthydietforhealthylife.eu/project/carbhealth) and also conducted a large weight loss study with different diets as part of the Mohn Nutrition Research Laboratory (Trond Mohn Foundation (formerly Bergen Research Foundation, https://www.uib.no/en/nutrition/120713/about-mohn-nutrition-research-lab)

Furthermore, I am interested in the health effects of microplastics. Here we conduct research using laboratory  animals as models for investigating the health effects of microplastics, but also conduct observational studies in humans. We received support from UiB through the marine priority area and the Marie Curie program SEAS https://www4.uib.no/en/research/research-projects/seas-shaping-european-research-leaders-for-marine-sustainability

I am the head of NutriNOR (National Research School in Nutrition, funded by the Research Council of Norway) (https://www.uib.no/en/rs/nutrinor), which is open for all PhD students in nutrition and food science and has the aim to improve the scientific and professional education of PhD candidates by summer schools, PhD conferences, internships, and leadership training. NutriNOR joins more than 20 partners and includes about 70 PhD candidates.

Several presentations in Norway and other countries, for example: 

https://www.dge.de/veranstaltungen/tagungen/arbeitstagung-2025/

Member of the "systematic review centre" for the Nordic Nutrition Recommendations 2023 (aktive from 2020-2023)

Vice president of the Norwegian Nutrition Society https://norskselskapforernaering.no/

Bord member of the Plastic nettwork at UiB, organisation of the annual symposium  

Courses

Bachelorprogram in Human Nutrition

NUTR100   Introduction to clinical nutrition

Nutr203     Nutrition physiology

Masterprogram in Clinical Nutrition

ELMED326   Genetic disorders in Nutrient Metabolism

NUCLI390A og B Master thesis in Clinical Nutrition 

See a complete overview of publications in Cristin.

Selected Publications

2025

Hjorth T, Schadow A, Revheim I, Spielau U, Meyer K, Rieder A, Varela P, Ballance S, Koerner A, Landberg R, Buyken AE, Dierkes J, Rosendahl-Riise H. Effectiveness of regular oat β-glucan-enriched bread compared with whole-grain wheat bread on long-term glycemic control in adults at risk of type 2 diabetes: a randomized controlled trial. Am J Clin Nutr. 2025 Sep;122(3):724-732. doi: 10.1016/j.ajcnut.2025.06.018.

2024

Trollebø MA, Tangvik RJ, Skeie E, Grønning MK, Nygård O, Eagan TML, Dierkes J. Malnutrition as a prognostic factor for 2-year mortality in hospitalized patients in Norway: A matched cohort study. JPEN J Parenter Enteral Nutr. 2024 Apr;48(3):308-317. doi: 10.1002/jpen.2619.

2023

Sabir Z, Dierkes J, Hjartåker A, Rosendahl-Riise H. The association of dietary patterns with muscle mass and strength in old age: The Hordaland Health Study. Eur J Nutr. 2023 Oct;62(7):2739-2750. doi: 10.1007/s00394-023-03206-9.

2022

Ballance S, Mæhre HK, Rieder A, Arslan Lied G, Hindar Tvedt EK, Dierkes J. The solution properties of galactomannan after simulated digestion of guar fortified bread predict the extent of postprandial insulin reduction in healthy adult overweight subjects. Food Funct. 2022 Oct 3;13(19):9810-9821. doi: 10.1039/d2fo01762h. 

Toto B, Refosco A, O'Keeffe M, Barkhald ØH, Brønstad A, Lied GA, Yadetie F, Goksøyr A, Kögel T, Dierkes J. Intestinal permeability and gene expression after polyethylene and polyamide microplastic ingestion in Wistar rats. Toxicol Lett. 2022 Nov 1;370:35-41. doi: 10.1016/j.toxlet.2022.09.002.

2020

Van Parys A, Lysne V, Øyen J, Dierkes J, Nygård OK. No effect of plasma trimethylamine N-Oxide (TMAO) and plasma trimethyllysine (TML) on the association between choline intake and acute myocardial infarction risk in patients with stable angina pectoris. Hum Nutr Metab 2020; 21:

Van Parys A, Lysne V, Svingen GFT, Ueland PM, Dhar I, Øyen J, Dierkes J, Nygård OK. Dietary choline is related to increased risk of acute myocardial infarction in patients with stable angina pectoris. Biochimie. 2020 Jun;173:68-75.

Weikert C, Trefflich I, Menzel J, Obeid R, Longree A, Dierkes J, Meyer K, Herter-Aeberli I, Mai K, Stangl GI, Müller SM, Schwerdtle T, Lampen A, Abraham K: Vitamin and mineral status in a vegan diet. Dtsch Arztebl Int 2020; 117: 575–82.

2019

H. Rosendahl-Riise, T. Karlsson, CA Drevon, EM Apalset, OK Nygård, GS Tell, J. Dierkes. Total and lean fish intake is positively associated with bone mineral density in older women in the community-based Hordaland Health Study. Eur J Nutr. 2019; 58:1403-1413

2018

E. Degerud, O. Nygård, S. de Vogel, R. Hoff, GFT. Svingen, ER. Pedersen, DW. Nilsen, JE.   Nordrehaug, Ø. Midttun, PM. Ueland, J. Dierkes. Plasma 25-hydroxyvitamin D and mortality in patients with suspected stable angina pectoris. J Clin Endocrinol Metab. 2018; 103: 1161-1170

H. Rosendahl-Riise, G. Sulo, T. Karlsson, CA Drevon, J. Dierkes, GS Tell. Limited Benefit of Fish Consumption on Risk of Hip Fracture among Men in the Community-Based Hordaland Health Study. Nutrients. 2018 Jul 6;10(7). pii: E873.

2017

T. Karlsson, E. Strand, J. Dierkes, C.A. Drevon, J. Øyen, Ø. Midttun, P.M. Ueland, O.A. Gudbrandsen, E.R. Pedersen, O. Nygård. Associations between intake of fish and n-3 long-chain polyunsaturated fatty acids and plasma metabolites related to the kynurenine pathway in patients with coronary artery disease. Eur J Nutr. 2017;56:261-272

H. Rosendahl-Riise, U. Spielau, A. H. Ranhoff, O. A. Gudbrandsen, J. Dierkes: Vitamin D supplementation and its influence on muscle strength and mobility in community-dwelling older persons: a systematic review and meta-analysis. J Hum Nutr Diet 2017;30:3-15

T. Karlsson, H. Rosendahl-Riise, J. Dierkes, C.A. Drevon, G.S. Tell, O. Nygård: Associations between fish intake and the metabolic syndrome and its components among middle-aged men and women: the Hordaland Health Study. Food Nutr Res. 2017 Jul 3;61(1):1347479. eCollection 2017.

T.R. Haugsgjerd, J. Dierkes, S.E. Vollset,K.J. Vinknes, O.K. Nygård, R. Seifert, G. Sulo, G.S. Tell. Association between weight change and mortality in community living older people followed for up to 14 years. The Hordaland Health Study (HUSK). J Nutr Health Ageing 2017;21:909-917

2016

E. Degerud, R. Hoff, O. Nygård, E. Strand, DW. Nilsen, E. Nordrehaug, Ø. Midttun, PM. Ueland, S. de Vogel, J. Dierkes. Cosinor modelling of seasonal variation in 25-hydroxyvitamin D concentrations in cardiovascular patients in Norway. Eur J Clin Nutr. 2016 Apr;70(4):517-22

U. Lehmann, A. Riedel, F. Hirche, C. Brandsch, M. Girndt, C. Ulrich, E. Seibert, C. Henning, MA. Glomb, J. Dierkes, GI Stangl. Vitamin D(3) supplementation: Response and predictors of vitamin D(3) metabolites - A randomized controlled trial. Clin Nutr. 2016;35:351-358