For those looking to lose weight (and do it fast), the ketogenic diet, more commonly known as “keto,” is a godsend. Originally designed to help people with certain neurological conditions, people on the keto diet consume a high-fat, low-carb, and moderate-protein diet to lose weight, gain mental clarity, and improve energy levels.
While a number of health benefits have been reported, a recently published study Cell Reports Medicine It is reported that people on the keto diet experience a decrease in friendly gut bacteria in addition to an increase in cholesterol levels.
Researchers at the University of Bath's Centre for Nutrition, Exercise and Metabolism followed various diets in 53 participants over a 12-week period to see how they might affect their overall health. During this time, individuals followed either a moderate-sugar diet (control), a low-sugar diet (less than 5 percent of calories from sugar) or a low-carb ketogenic diet (less than 8 percent of calories from carbohydrates).
The researchers found that after 12 weeks, participants on the ketogenic diet not only experienced increases in small and medium-sized LDL (“bad” cholesterol), but also increased apolipoprotein B (apoB), which is responsible for plaque formation in our arteries.
“Despite reducing fat mass, the ketogenic diet increased levels of negative fats in the blood of our participants. This can lead to long-term health problems, such as an increased risk of heart disease and stroke if continued over many years,” said lead researcher Dr. Aaron Hengist.
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They also found that the keto diet changed the structure of the gut microbiome, particularly bifidobacteria, which can help produce important B vitamins, inhibit harmful bacteria and lower cholesterol levels.
“Dietary fibre is essential for the survival of beneficial gut bacteria such as bifidobacteria,” says Dr Russell Davies, who led the microbiome research. “The ketogenic diet reduced fibre intake to around 15g per day, half the NHS recommended amount. This reduction in bifidobacteria can contribute to important long-term health outcomes, including an increased risk of digestive disorders such as irritable bowel disease, an increased risk of gut infections and compromised immune function.”
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But the results weren’t all bad. The study also discovered that both sugar-restrictive and ketogenic diets led to fat loss regardless of participants’ activity levels, proving that the keto diet can still be a valuable way to lose weight for some people.
“The ketogenic diet is effective for fat loss, but it has a range of metabolic and microbiome effects that may not suit everyone,” says Professor Dylan Thompson, who led the research.
Although more research is needed to determine the long-term effects of the keto diet, the researchers agree that if you're going to choose one of the diets they've tested for weight loss, low-sugar ones are a better option for most people.
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