Comparison of Ketogenic Diets with and without Ketone Salts versus a Low-Fat Diet: Liver Fat Responses in Overweight Adults

Nutrients. 2021 Mar 17;13(3):966. doi: 10.3390/nu13030966.

Abstract

Ketogenic diets (KDs) often contain high levels of saturated fat, which may increase liver fat, but the lower carbohydrate intake may have the opposite effect. Using a controlled feeding design, we compared liver fat responses to a hypocaloric KD with a placebo (PL) versus an energy-matched low-fat diet (LFD) in overweight adults. We also examined the added effect of a ketone supplement (KS). Overweight adults were randomized to a 6-week KD (KD + PL) or a KD with KS (KD + KS); an LFD group was recruited separately. All diets were estimated to provide 75% of energy expenditure. Weight loss was similar between groups (p > 0.05). Liver fat assessed by magnetic resonance imaging decreased after 6 week (p = 0.004) with no group differences (p > 0.05). A subset with nonalcoholic fatty liver disease (NAFLD) (liver fat > 5%, n = 12) showed a greater reduction in liver fat, but no group differences. In KD participants with NAFLD, 92% of the variability in change in liver fat was explained by baseline liver fat (p < 0.001). A short-term hypocaloric KD high in saturated fat does not adversely impact liver health and is not impacted by exogenous ketones. Hypocaloric low-fat and KDs can both be used in the short-term to significantly reduce liver fat in individuals with NAFLD.

Keywords: NAFLD; exogenous ketones; ketogenic diet; liver fat; low carbohydrate.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Diet, Fat-Restricted* / methods
  • Diet, Ketogenic* / methods
  • Dietary Supplements*
  • Fats / analysis*
  • Fats / metabolism
  • Female
  • Humans
  • Ketones / therapeutic use*
  • Liver / chemistry*
  • Liver / diagnostic imaging
  • Liver / metabolism
  • Magnetic Resonance Imaging
  • Male
  • Overweight / diet therapy*
  • Overweight / metabolism

Substances

  • Fats
  • Ketones

Grants and funding