In people with prediabetes or type 2 diabetes, a diet enriched in monounsaturated fat (22–28% of energy intake; primarily from olive oil) has been shown to reduce liver fat compared to a diet enriched in fiber and slightly higher in carbohydrates, independent of changes in body weight.[1][2] In addition, saturated fats have been shown to increase liver fat compared to polyunsaturated fats.[3][4][5][6]
Collectively, these findings indicate that unsaturated fat may have a positive effect on liver fat, especially compared to saturated fat. However, in each of these studies, body weight either did not change (the studies on monounsaturated fat) or increased (the studies on polyunsaturated fat).
A randomized controlled trial in participants with abdominal obesity found that a hypocaloric diet enriched in monounsaturated and polyunsaturated fat (13.4% and 7.7% of energy intake) and reduced in saturated fat (8.3% of energy intake) produced similar reductions in liver fat as a hypocaloric diet that was lower in monounsaturated and polyunsaturated fat (9.3% and 4.1% of energy intake) and higher in saturated fat (14.9% of energy intake).[7] Although it’s possible that the difference in unsaturated fat intake wasn’t large enough to produce significant differences in liver fat between groups, these findings suggest that the potent effects of energy restriction on liver fat far outweigh the effects of the type of fat consumed.
References
- ^Isabel Errazuriz, Simmi Dube, Michael Slama, Roberto Visentin, Sunita Nayar, Helen O'Connor, Claudio Cobelli, Swapan Kumar Das, Ananda Basu, Walter Karl Kremers, John Port, Rita BasuRandomized Controlled Trial of a MUFA or Fiber-Rich Diet on Hepatic Fat in PrediabetesJ Clin Endocrinol Metab.(2017 May 1)
- ^Lutgarda Bozzetto, Anna Prinster, Giovanni Annuzzi, Lucia Costagliola, Anna Mangione, Alessandra Vitelli, Raffaella Mazzarella, Margaret Longobardo, Marcello Mancini, Carlo Vigorito, Gabriele Riccardi, Angela A RivelleseLiver fat is reduced by an isoenergetic MUFA diet in a controlled randomized study in type 2 diabetic patientsDiabetes Care.(2012 Jul)
- ^Fredrik Rosqvist, Joel Kullberg, Marcus Ståhlman, Jonathan Cedernaes, Kerstin Heurling, Hans-Erik Johansson, David Iggman, Helena Wilking, Anders Larsson, Olof Eriksson, Lars Johansson, Sara Straniero, Mats Rudling, Gunnar Antoni, Mark Lubberink, Marju Orho-Melander, Jan Borén, Håkan Ahlström, Ulf RisérusOvereating Saturated Fat Promotes Fatty Liver and Ceramides Compared With Polyunsaturated Fat: A Randomized TrialJ Clin Endocrinol Metab.(2019 Dec 1)
- ^Rosqvist F, Iggman D, Kullberg J, Cedernaes J, Johansson HE, Larsson A, Johansson L, Ahlström H, Arner P, Dahlman I, Risérus UOverfeeding polyunsaturated and saturated fat causes distinct effects on liver and visceral fat accumulation in humansDiabetes.(2014 Jul)
- ^Luukkonen PK, Sädevirta S, Zhou Y, Kayser B, Ali A, Ahonen L, Lallukka S, Pelloux V, Gaggini M, Jian C, Hakkarainen A, Lundbom N, Gylling H, Salonen A, Orešič M, Hyötyläinen T, Orho-Melander M, Rissanen A, Gastaldelli A, Clément K, Hodson L, Yki-Järvinen HSaturated Fat Is More Metabolically Harmful for the Human Liver Than Unsaturated Fat or Simple Sugars.Diabetes Care.(2018-08)
- ^Bjermo H, Iggman D, Kullberg J, Dahlman I, Johansson L, Persson L, Berglund J, Pulkki K, Basu S, Uusitupa M, Rudling M, Arner P, Cederholm T, Ahlström H, Risérus UEffects of n-6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trialAm J Clin Nutr.(2012 May)
- ^Sophie Schutte, Diederik Esser, Els Siebelink, Charlotte J R Michielsen, Monique Daanje, Juri C Matualatupauw, Hendriek C Boshuizen, Marco Mensink, Lydia A Afman, Wageningen Belly Fat Study teamDiverging metabolic effects of two energy restricted diets differing in nutrient quality: a 12-week randomized controlled trial in subjects with abdominal obesityAm J Clin Nutr.(2022 Jan 31)