Plain language summary
High sugar diets can lead to increased fat accumulation in the liver and skeletal muscles, as intrahepatocellular lipid (IHCL) and intramyocellular lipid (IMCL) respectively. Elevation in these lipid concentrations is associated with an increased risk of various chronic diseases. The aim of this randomised crossover trial was to assess whether the consequences of a high sugar diet differed according to the protein and fat composition in 12 healthy adults. At the beginning of each trial period, participants consumed a 3-day weight maintenance diet followed by a 6-day high calorie, high sugar diet consisting of either low protein-high fat or high protein-low fat with a 4-8 week washout period. IHCL and IMCL concentrations, energy expenditure and blood metabolites were monitored after each weight maintenance diet and after each 6-day intervention diet period. This study found that both diets led to increased lipid concentrations, most notably the in liver cells. Lipid increases induced by the high protein-low fat diet were significantly lower than those induced by the low protein-high fat diet. Based on these results, the authors conclude that when overfed on a high sugar diet, high protein-low fat markedly reduces the amount of fat accumulation in liver and muscle cells and suggest that either dietary protein may have a protective effect of sugar and fat may have an additive adverse effect.
Abstract
Sucrose overfeeding increases intrahepatocellular (IHCL) and intramyocellular (IMCL) lipid concentrations in healthy subjects. We hypothesized that these effects would be modulated by diet protein/fat content. Twelve healthy men and women were studied on two occasions in a randomized, cross-over trial. On each occasion, they received a 3-day 12% protein weight maintenance diet (WM) followed by a 6-day hypercaloric high sucrose diet (150% energy requirements). On one occasion the hypercaloric diet contained 5% protein and 25% fat (low protein-high fat, LP-HF), on the other occasion it contained 20% protein and 10% fat (high protein-low fat, HP-LF). IHCL and IMCL concentrations (magnetic resonance spectroscopy) and energy expenditure (indirect calorimetry) were measured after WM, and again after HP-LF/LP-HF. IHCL increased from 25.0 ± 3.6 after WM to 147.1 ± 26.9 mmol/kg wet weight (ww) after LP-HF and from 30.3 ± 7.7 to 57.8 ± 14.8 after HP-LF (two-way ANOVA with interaction: p < 0.001 overfeeding x protein/fat content). IMCL increased from 7.1 ± 0.6 to 8.8 ± 0.7 mmol/kg ww after LP-HF and from 6.2 ± 0.6 to 6.9 ± 0.6 after HP-LF, (p < 0.002). These results indicate that liver and muscle fat deposition is enhanced when sucrose overfeeding is associated with a low protein, high fat diet compared to a high protein, low fat diet.
Methodological quality
Jadad score
:
3
Allocation concealment
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Not applicable
