According to a new nutritional study of people with type 2 diabetes mellitus by the German Institute for Human Nutrition, they found that a high protein diet can reduce liver fat by up to 48% within six weeks. Whether the diet is based on plant protein or animal protein does not matter. The findings were published in the international journal Gastroenterology.
Several studies worldwide have investigated the effects of high-protein diets on human metabolism. In many studies, scientists have observed beneficial effects on body weight, liver fat content, lipid levels, long-term blood sugar levels, and muscle mass. But some studies have also found that high protein intake can reduce insulin activity and affect kidney function. Since different studies have observed both positive and negative effects of high-protein diets, researchers at the German Institute for Human Nutrition have asked whether protein source is the determinant of these different effects. In this study, they examined the metabolic effects of two high-protein diets on 37 people aged 49 to 78 with type 2 diabetes mellitus, most of whom also had fatty liver disease. The only difference between these two high-protein diets is the source of protein (plant and animal).
To ensure that the participants’ weight remained stable during the study, the researchers adjusted the total number of calories for each person and randomly assigned the participants to choose one of the high-protein diets. The results showed that all study participants benefited from the high-protein diet, regardless of protein source, and no adverse effects of the high-protein diet on kidney function and glucose metabolism were observed. Liver fat content decreased most significantly, with half of the participants dropping by more than 50%, while the researchers also observed beneficial changes in liver lipid metabolism, improved insulin sensitivity, and a significant decrease in blood FGF21 levels. Previous studies have shown that FGF21 produced in the liver can affect multiple tissues, including adipose tissue, especially in overweight and obese people, whose blood levels are often high.
The researchers say larger, longer-term studies are needed to better understand the metabolic mechanisms and long-term effects of a high-protein diet, and to see if younger patients may also benefit from the diet.
