title: Strong and persistent effect on liver fat with a Paleolithic diet during a two-year intervention.
abstract: Our objective was to investigate changes in liver fat and insulin sensitivity during a 2-year diet intervention. An ad libitum Paleolithic diet (PD) was compared with a conventional low-fat diet (LFD).
  
  
  
  Seventy healthy, obese, postmenopausal women were randomized to either a PD or a conventional LFD. Diet intakes were ad libitum. Liver fat was measured with proton magnetic resonance spectroscopy. Insulin sensitivity was evaluated with oral glucose tolerance tests and calculated as homeostasis model assessment-insulin resistance (HOMA-IR)/liver insulin resistance (Liver IR) index for hepatic insulin sensitivity and oral glucose insulin sensitivity (OGIS)/Matsuda for peripheral insulin sensitivity. All measurements were performed at 0, 6 and 24 months. Forty-one women completed the examinations for liver fat and were included.
  
  
  
  Liver fat decreased after 6 months by 64% (95% confidence interval: 54-74%) in the PD group and by 43% (27-59%) in the LFD group (P<0.01 for difference between groups). After 24 months, liver fat decreased 50% (25-75%) in the PD group and 49% (27-71%) in the LFD group. Weight reduction between baseline and 6 months was correlated to liver fat improvement in the LFD group (rs=0.66, P<0.01) but not in the PD group (rs=0.07, P=0.75). Hepatic insulin sensitivity improved during the first 6 months in the PD group (P<0.001 for Liver IR index and HOMA-IR), but deteriorated between 6 and 24 months without association with liver fat changes.
  
  
  
  A PD with ad libitum intake had a significant and persistent effect on liver fat and differed significantly from a conventional LFD at 6 months. This difference may be due to food quality, for example, a higher content of mono- and polyunsaturated fatty acids in the PD. Changes in liver fat did not associate with alterations in insulin sensitivity.
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Otten
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Mellberg
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Ryberg
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Sandberg
authors.affiliation: Department of Radiology, Uppsala University, Uppsala, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Kullberg
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Lindahl
authors.affiliation: Department of Food and Nutrition, and Sport Science, University of Gothenburg, Gothenburg, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Larsson
authors.affiliation: Center for Medical Technology and Radiation Physics, Umeå University Hospital, Umeå, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Hauksson
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Olsson
mesh_terms: D001786:Blood Glucose; D001794:Blood Pressure / Q000187:drug effects; D018752:Diet, Fat-Restricted; D066046:Diet, Paleolithic; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008099:Liver / Q000187:drug effects / Q000473:pathology*; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000178:diet therapy* / Q000209:etiology / Q000473:pathology; D009765:Obesity / Q000150:complications / Q000178:diet therapy* / Q000473:pathology; D017698:Postmenopause; D013548:Sweden; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D001786:Blood Glucose; D008055:Lipids