It’s a question that many nutrition researchers have spent decades debating: which diet is best for weight loss?
Now, researchers at the University of Illinois have made a discovery that they believe could help provide the answer.
The scientists found that mice feed made up of one of two types of protein were associated with having less body fat than a standard diet.
They also discovered that eating a high-protein diet can have a beneficial effect on the trillions of healthy bacteria in the gut, which have been linked to hunger and appetite control.
The study, carried out on mice, aimed to determine how protein-heavy diets affect the animal’s gut microbiome and body make-up, including overall weight and fat.
Mice fed a diet made up largely of different types of proteins weighed less with lower fat mass. The proteins they consumed are found in most meat, eggs, and several types of fish
Scientists conducted a month-long experiment on 16 mice. For the first two weeks of the experiment, the mice were fed a standard diet of mice chow made up mostly of carbohydrates.
For the following two weeks, they were broken into four groups given new food that contained one of two types of protein, both of which can be found in meat, poultry, and seafood.
Scientists collected daily samples of the mices’ fecal matter to monitor the proportion of healthy gut bacteria, as well as measurements of their body fat.
At the end of the study period, it was revealed that the mice eating the diets high in protein experienced more loss in both bodyweight and fat than those on the standard carb-heavy diets.
One type of protein came out on top as the most impactful – branched-chain amino acids, given to one of the groups.
Branched-chain amino acids are commonly found in chicken, beef, and turkey, salmon, tuna, shrimp, and milk.
They also found that undigested protein fermented in the gut, producing beneficial byproducts such as short-chain fatty acids, which help the body regulate appetite and absorb vitamins.
Previous studies have pointed to the positive effects of a protein-rich diet gut microbiome.
Fermentation of protein leads to the development of certain beneficial strains of bacterial such as lactobacillus, which can hunt down and destroy harmful bacterial.
Samson Adejumo, a biology doctoral candidate at the University of Illinois who led the research said the findings contribute towards a ‘crucial foundation’ in our understanding of how protein influences our gut microbiome, and ultimately our health.
Previous studies have found that an abundant gut microbiome can increase the rate at which at calories are burned and regulate hunger signals sent between the brain and the stomach.
It also modulates the movement of bile in the digestive tract, which plays a role in fat digestion and absorption.
While the experiment was conducted in mice, other research has come to the conclusion that increasing the amount of protein from food in one’s diet promotes muscle toning, growth, and strength.
Protein should account for 10 to 35 percent of daily calories, and athletes should consume one to two grams per kilogram of bodyweight, official guidance recommends.