For years, the ketogenic or keto diet got praised for its guaranteed weight loss. But researchers recently found that its downsides could be deadly to its followers.

A new study presented over the weekend at the American College of Cardiology’s Annual Scientific Session Together With the World Congress of Cardiology in New Orleans, Louisiana, suggested that a low-carb, high-fat diet could trigger a spike in “bad” or LDL cholesterol.

Too much LDL cholesterol leads to a buildup of plaque in the arteries, which significantly increases the risk of cardiovascular events, heart attacks, and strokes.

“Our study found that regular consumption of a self-reported diet low in carbohydrates and high in fat was associated with increased levels of LDL cholesterol — or 'bad' cholesterol — and a higher risk of heart disease,” lead author Iulia Iatan, M.D., Ph.D., said in a press release.

“To our knowledge, our study is one of the first to examine the association between this type of dietary pattern and cardiovascular outcomes,” added the attending physician-scientist at the Healthy Heart Program Prevention Clinic, St. Paul’s Hospital and University of British Columbia’s Centre for Heart Lung Innovation in Vancouver, Canada.

Iatan and her colleagues evaluated a keto-like diet for the study consisting of no more than 25% carbohydrates and over 45% fat. The composition of the low-carb, high-fat diet they studied was higher in carbs and lower in fat compared to the strict keto diet.

They analyzed data from 70,684 people enrolled in the U.K. Biobank, a large-scale prospective database with health information from half a million people living in the United Kingdom. The participants completed a diet questionnaire and had their blood drawn to check their cholesterol levels.

Based on the questionnaire responses, the team identified 305 participants whose diets matched their defined low-carb, high-fat diet. They also identified 1,220 individuals on a standard diet who matched the “keto” dieters by age and sex. The team compared data from the two groups.

“Among the participants on an [low-carb, high-fat] diet, we found that those with the highest levels of LDL cholesterol were at the highest risk for a cardiovascular event. Our findings suggest that people who are considering going on an [low-carb, high-fat] diet should be aware that doing so could lead to an increase in their levels of LDL cholesterol," Iatan said.

She continued, "Before starting this dietary pattern, they should consult a health care provider. While on the diet, it is recommended they have their cholesterol levels monitored and should try to address other risk factors for heart disease or stroke, such as diabetes, high blood pressure, physical inactivity and smoking.”

Carbohydrates are the “go-to” source of the body for fuel to provide energy for different activities. When carb intake is low, the body starts looking for other fuel sources, and it turns to fat for energy. When the liver breaks down fat, an alternative fuel source, called ketones, is formed. This is where the famous keto diet got its name, according to Fox News Digital.

Registered dietitian nutritionist Lindsay Allen, who was not involved in the study, told the outlet that though the findings may seem alarming, they just show that the keto diet is not for everyone.

"There's nothing inherently bad about the keto diet, as long as it's for the appropriate person, the consumption of fats are balanced, and the diet is cycled to allow for antioxidants and fiber. This study demonstrates that the keto diet definitely is not for everyone, and it would be helpful to seek guidance from a professional to make sure you're a good candidate,” Allen said.

Ketogenic diet
The ketogenic diet is a low-carb and high-fat diet that is often recommended to menopausal women to lose weight, but at what cost? MootikaLLC/Pixabay