Chinese researchers have reported high-protein diets help promote weight management by reducing levels of a particular gut bacteria linked to intestinal fat absorption.
The team at Shanghai’s University of Chinese Academy of Sciences investigated the causes of weight regain following weight loss from dieting, and noted that reducing levels of the specific gut bacteria – via a high-protein diet or antibiotics – could promote sustained weight loss after dietary restriction.
Previous studies of weight loss diets have reported ‘over 50% of weight loss is regained within 2 years and over 80% of lost weight is regained within 5 years’, noted medicalnewstoday.com.
The Chinese team, whose study was published in Nature Metabolism, examined the effects of diets with varying protein levels on fat levels in mice following dietary restriction.
They initially investigated how dietary restriction followed by limitless feeding affected fat mass – and found refeeding after dietary restriction led to a quick build-up of fat.
In further experiments, they noted increases in fat levels occurred due to increased fat absorption in the intestines – as opposed to increased food intake.
Next, they analysed blood samples from mice before, during and after short-term dietary restriction to identify potential ways to sustain weight loss – and found certain amino acids in the blood increased during and after dietary restriction.
To understand how protein levels may influence post-diet fat absorption, they fed mice a high- protein diet, normal-protein diet or low-protein diet after a short-term dietary restriction – and found high- protein diets were most effective in preventing quick weight regain and also partially maintained weight loss thereafter.
From further tests, they found high-protein diets decreased intestinal fat absorption.
When they analysed faecal samples from mice fed high amounts of protein and normal amounts of protein following dietary restriction, they found mice on normal diets had higher levels of Lactobacillus bacteria than mice on high-protein diets.
To see whether Lactobacillus levels influenced weight regain, the researchers treated mice with penicillin for a week before placing them on restrictive diets – and found penicillin reduced Lactobacillus without affecting other bacteria, and significantly reduced intestinal fat absorption afterward.
The researchers concluded targeting Lactobacillus after dietary restriction with a high-protein diet or antibiotics could prevent obesity after dieting.
Professor Tonia Vinton, who specialises in obesity at U.T. Southwestern Medical Center in Dallas, Texas commented: ‘This study suggests that after a short period of dietary restriction – such as intermittent fasting or very low- calorie dieting attempts – a high- protein diet may prevent weight regain by increasing Lascobacillus gut bacteria, which limits intestinal lipid absorption.’
