The Potential of a High Protein-Low Carbohydrate Diet to Preserve Intrahepatic Triglyceride Content in Healthy Humans

BACKGROUND Protein supplementation has been shown to reduce the increases in intrahepatic triglyceride (IHTG) content induced by acute hypercaloric high-fat and high-fructose diets in humans. OBJECTIVE To assess the effect of a 12-wk iso-energetic high protein-low carbohydrate (HPLC) diet compared with an iso-energetic high carbohydrate-low protein (HCLP) diet on IHTG content in healthy non-obese subjects, at a constant body weight. DESIGN Seven men and nine women [mean ± SD age: 24 ± 5 y; BMI: 22.9 ± 2.1 kg/m2] were randomly allocated to a HPLC [30/35/35% of energy (En%) from protein/carbohydrate/fat] or a HCLP (5/60/35 En%) diet by stratification on sex, age and BMI. Dietary guidelines were prescribed based on individual daily energy requirements. IHTG content was measured by 1H-magnetic resonance spectroscopy before and after the dietary intervention. RESULTS IHTG content changed in different directions with the HPLC (CH2H2O: 0.23 ± 0.17 to 0.20 ± 0.10; IHTG%: 0.25 ± 0.20% to 0.22 ± 0.11%) compared with the HCLP diet (CH2H2O: 0.34 ± 0.20 vs. 0.38 ± 0.21; IHTG%: 0.38 ± 0.22% vs. 0.43 ± 0.24%), which resulted in a lower IHTG content in the HPLC compared with the HCLP diet group after 12 weeks, which almost reached statistical significance (P = 0.055). CONCLUSIONS A HPLC vs. a HCLP diet has the potential to preserve vs. enlarge IHTG content in healthy non-obese subjects at a constant body weight. TRIAL REGISTRATION Clinicaltrials.gov NCT01551238.