Associations between low-carbohydrate and low-fat diets and hepatic steatosis

This study assessed the cross-sectional associations of low-carbohydrate diets (LCDs) and low-fat diets (LFDs) with hepatic steatosis in the National Health and Nutrition Examination Survey.

Diet was measured using the 24-hour recalls. Hepatic steatosis was defined by vibration-controlled transient elastography. The odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression. Substitution analysis was performed using the leave-one-out model.

Participants with higher adherence scores (comparing extreme tertiles) for an overall (OR = 0.76, 95% CI: 0.61-0.96, p_trend  = 0.049) or a healthful LCD (OR = 0.61, 95% CI: 0.43-0.87, p_trend  < 0.001) exhibited lower odds of steatosis. Replacing 5% of the energy from carbohydrates with total fat and protein (OR = 0.91, 95% CI: 0.83-0.99) or unsaturated fat and plant protein (OR = 0.89, 95% CI: 0.84-0.94) was associated with lower steatosis prevalence. High overall (OR = 1.65, 95% CI: 1.13-2.40, p_trend  = 0.006) or unhealthful (OR = 1.41, 95% CI: 1.10-1.80, p_trend  < 0.001) LFD scores were associated with increased likelihood of steatosis.

These findings suggest that the associations between LCDs and LFDs and steatosis may depend on the quality and food sources of the macronutrients.