title: Overfeeding polyunsaturated and saturated fat causes distinct effects on liver and visceral fat accumulation in humans.
abstract: Excess ectopic fat storage is linked to type 2 diabetes. The importance of dietary fat composition for ectopic fat storage in humans is unknown. We investigated liver fat accumulation and body composition during overfeeding saturated fatty acids (SFAs) or polyunsaturated fatty acids (PUFAs). LIPOGAIN was a double-blind, parallel-group, randomized trial. Thirty-nine young and normal-weight individuals were overfed muffins high in SFAs (palm oil) or n-6 PUFAs (sunflower oil) for 7 weeks. Liver fat, visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (SAT), total adipose tissue, pancreatic fat, and lean tissue were assessed by magnetic resonance imaging. Transcriptomics were performed in SAT. Both groups gained similar weight. SFAs, however, markedly increased liver fat compared with PUFAs and caused a twofold larger increase in VAT than PUFAs. Conversely, PUFAs caused a nearly threefold larger increase in lean tissue than SFAs. Increase in liver fat directly correlated with changes in plasma SFAs and inversely with PUFAs. Genes involved in regulating energy dissipation, insulin resistance, body composition, and fat-cell differentiation in SAT were differentially regulated between diets, and associated with increased PUFAs in SAT. In conclusion, overeating SFAs promotes hepatic and visceral fat storage, whereas excess energy from PUFAs may instead promote lean tissue in healthy humans.
authors.affiliation: Clinical Nutrition and Metabolism, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Rosqvist
authors.affiliation: Clinical Nutrition and Metabolism, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, SwedenCenter for Clinical Research Dalarna, Falun, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Iggman
authors.affiliation: Department of Radiology, Uppsala University, Uppsala, Sweden.
authors.forename: Joel
authors.initials: J
authors.lastname: Kullberg
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala Biomedical Center, Uppsala, Sweden.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Cedernaes
authors.affiliation: Clinical Nutrition and Metabolism, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Hans-Erik
authors.initials: HE
authors.lastname: Johansson
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
authors.affiliation: Department of Radiology, Uppsala University, Uppsala, SwedenResearch and Development, AstraZeneca, Molndal, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Johansson
authors.affiliation: Department of Radiology, Uppsala University, Uppsala, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Ahlström
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Arner
authors.affiliation: Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Dahlman
authors.affiliation: Clinical Nutrition and Metabolism, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden ulf.riserus@pubcare.uu.se.
authors.forename: Ulf
authors.initials: U
authors.lastname: Risérus
mesh_terms: D000328:Adult; D001823:Body Composition / Q000187:drug effects; D005227:Fatty Acids / Q000008:administration & dosage*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000187:drug effects / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects* / Q000235:genetics; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D044343:Overnutrition / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome / Q000187:drug effects; D014781:Viscera / Q000187:drug effects* / Q000378:metabolism; D055815:Young Adult
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated