Keto diet helps in weight loss but also raises cholesterol levels

Eating a keto diet, which involves eating most of the calories from fat and very few from carbohydrates, leads to fat loss, but it can also clog blood vessels and affect the gut microbiome. badly.

Also known as the ketogenic diet, this diet forces the body to use a different type of fat. Instead of relying on sugar from carbohydrates, it begins to rely on ketone bodies, a type of fat that the liver produces from stored fat, which leads to weight loss.

Previous studies have tracked the health outcomes of people who follow a ketogenic diet compared to those who don’t, showing that it has both risks and benefits.

Now, Javier Gonzalez from the University of Bath in the UK and his colleagues have conducted a randomized controlled trial, the best type of clinical evidence. The researchers recruited 53 people with an average age of 34, none of whom were obese. They gave a choice of about a third to eat a ketogenic diet, where all types of carbohydrates made up less than 8 percent of their energy and fat made up more than 70 percent.

Another third of the participants were told to eat a low-sugar diet, where “free” sugar – the type of carbohydrate found in foods such as syrups, cakes and biscuits – made up part of the 5 percent of their energy is free. – carbohydrate sugar and fat were 45 percent and 35 percent, respectively.

The remaining third ate foods with moderate amounts of sugar, making up only 20 percent of their energy intake, while carbohydrates and fats accounted for 30 and 35 percent respectively. successively. These participants served as the control group. Protein consumption was between 15 and 18 percent of all meals.

A month later, X-rays revealed that those on the ketogenic diet had lost 1.6 kilograms of fat, on average. The team verified that participants followed the ketogenic diet by measuring levels of ketone bodies in their blood, urine and breath. Food diaries also measure food adherence.

Meanwhile, those who ate a low-sugar diet lost 1 kg of fat, on average, while those who ate a moderate diet lost some fat. By having the participants wear activity monitors at certain times and by measuring their energy levels, the team found that fat loss was caused by eating fewer calories, rather than exercise more, something that was not clear before, says Gonzalez.

But even though there was greater fat loss in the ketogenic group, these people had 16 percent higher “low-density lipoprotein” (LDL) “bad” cholesterol than of the control group. They also had 26 percent higher levels of a protein called apolipoprotein B, which clogs blood vessels and increases the risk of heart-related events. Conversely, those on a low-sugar diet had 10 percent lower LDL cholesterol and no change in their apolipoprotein B, compared to in the control group.

The researchers also found that, compared to a diet with moderate sugar, those who ate a ketogenic diet had reduced levels of a type of intestinal bacteria called. Bifidobacteria, which helps produce B vitamins and has been linked to a stronger immune system. This was not the case for those who ate a low-sugar diet. That’s probably because those on the ketogenic diet ate less, more fiber Bifidobacteria conditions, says Gonzalez.

But whether the ketogenic diet actually affects the gut microbiome is unclear, because no one knows exactly what it is or the full effects of Bifidobacteria is, says Natasha Scholer at Great Ormond Street Hospital in London.

In addition, although high levels of apolipoprotein B are concerning, the increased cholesterol observed in the study is not necessarily dangerous if it does not reach dangerous thresholds, says Scholer.

Longer-term research is also needed to determine whether the benefits of ketogenic weight loss outweigh the potential problems with cholesterol and gut health among obese people, says Scholer. .

Finally, the biggest challenge to losing weight among those who are overweight or obese is sticking to a diet, says Scholer. “Whether it’s a normal carbohydrate diet but fewer calories, or the same amount of calories and fewer carbohydrates – if you stick to it, in general, you’ll lose weight. “

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