Consumption of a whey protein-enriched diet may prevent hepatic steatosis associated with weight gain in elderly women

• Modest whey protein intake does not reduce weight in healthy elderly women.
• Modest whey protein intake does not reduce hepatic steatosis.
• Modest whey protein intake does not reduce prevalence of fatty liver disease.
• Modest protein intake may prevent hepatic steatosis worsening with weight gain.

Background and aimsProtein consumption has been associated with cardio-metabolic benefits, including weight loss and improved insulin sensitivity, and may have potential benefits for individuals with fatty liver disease (FLD). We investigated the effect of increasing dietary protein intake from whey relative to carbohydrate on hepatic steatosis.Methods and resultsA two-year randomized, double-blind, placebo-controlled trial of 30 g/day whey protein-supplemented beverage (protein) or an energy-matched low-protein high-carbohydrate beverage (control) for cardio-metabolic and bone health in 219 healthy elderly women, recruited from the Western Australian general population. Hepatic steatosis was quantified using computed tomographic liver-to-spleen (L/S) ratio. FLD was defined as liver-to-spleen difference <10 Hounsfield units. At baseline, FLD prevalence was 11.4%. Control and protein groups were similar in body mass index (BMI), insulin resistance, L/S ratio and FLD prevalence at baseline. At two-years, dietary protein increased by 20 g in the protein, but not the control, group. Total energy intake and physical activity remained similar between groups. At two-years, BMI and FLD prevalence increased in both groups, with no between group differences. L/S ratio increased in control, but not protein, group at two-years, with no between group differences. In a within group comparison, change in BMI correlated with changes in L/S ratio in control (r = 0.37, P = 0.0007), but not with protein group (r = 0.04, P = 0.73).ConclusionIncreasing dietary protein intake from whey relative to carbohydrate does not reduce weight, hepatic steatosis or the prevalence of FLD in elderly women. However, it may prevent worsening of hepatic steatosis associated with weight gain.Clinical trials registrationAustralian New Zealand Clinical Trials Registry (Registration no. ACTRN012607000163404).