High dietary protein intake results in lower intra hepatic lipid content in healthy humans on a hypercaloric high‐fat diet

Abstract

High‐protein diets may improve regulation of body weight and glucose homeostasis and, at least in animals, reduce intra hepatic lipid content. Our objective was to reduce intra hepatic lipids (IHL) in healthy humans, by increasing protein (P) intake at the expense of carbohydrates (CH), in a high‐fat‐hypercaloric‐diet.A strictly controlled dietary intervention was performed in lean healthy subjects, who were randomly assigned to the intervention groups. One group received a balanced‐diet (BD‐group; n=10) (28 en% fat; 17 en% P; 55 en% CH) for 4 weeks. The other group (n=17) received a hypercaloric high‐fat diet (HD‐group; + 2 MJ per day, 40 en% fat) in a 2‐week cross‐over design, with a high protein content (HP; 26 en% P) or a normal protein content (NP; 15 en% P) and vice versa.On the HD diet there was a trend for lower IHL on HP compared to NP (difference 0.2 %, p=0.08); and a trend for increased IHL after BD compared to HD was seen (difference 0.13 %, p=0.06). Body weight did not differ between HP and NP, however fat mass was lower (−0.27 kg, p=0.02) and lean mass was higher (+0.52 kg, p=0.003) on HP compared to NP. Fasting insulin sensitivity and plasma triglyceride levels did not differ between protein diets.To conclude, high dietary protein intake, at the expense of carbohydrates, resulted in lower IHL in healthy humans, receiving a hypercaloric high‐fat diet. This research was supported by the Dutch Dairy Organisation (NZO).