Keto dieters may take a punch to the gut from this.
The trendy low-carb, high-fat diet among athletes, bodybuilders, and some celebrities has been shown in new studies to increase cholesterol and decrease good gut flora.
The study’s lead author, Dylan Thompson of the University of Bath, stated, “The ketogenic diet is effective for fat loss, but it comes with varied metabolic and microbiome effects that may not suit everyone.” Cell Reports Medicine was published on Monday.
53 healthy adults participated in the 12-week trial and followed one of three diets: moderate sugar, low sugar (less than 5% of calories from sugar), or keto (less than 8% of calories from carbohydrates).
Apolipoprotein B, which can lead to plaque accumulation in arteries, raised cholesterol levels, and Bifidobacteria—carb-loving bacteria that aid in fiber digestion, nutrition absorption, and immunity—were all reduced during the ketogenic diet.
“The ketogenic diet decreased daily fiber intake to approximately 15 grams,” said study leader Dr. Russell Davies.
“There could be serious long-term health effects from this decrease in Bifidobacteria, including an elevated risk of intestinal infections, weakened immune systems, and digestive disorders like irritable bowel disease,” he continued.
A lower-sugar diet is what the experts advise instead, claiming that it encourages fat loss “without apparent negative health impacts.”
In 12 weeks, low-sugar dieters lost an average of 4.6 pounds, compared to 6.4 pounds lost by keto dieters.
However, the sugar-restricted diet dramatically reduced cholesterol without appreciably changing gut flora.
This is not the first study investigating the potential gastrointestinal effects of a ketogenic diet. The University of California, San Francisco found in 2020 that a brief ketogenic diet led to a drop in Bifidobacteria.
This decline may be harmful to colon health and increase the risk of obesity, Type 2 diabetes, and depression, according to a 2022 analysis.
While some medical professionals caution that the keto diet is an unsustainable, quick-fix approach, it has been proved to be helpful in certain situations. For example, it can lower blood pressure, reduce inflammation, and help control seizures in children with epilepsy.
