In recent years, the keto diet has been proven to be beneficial when it comes to losing weight. The theory behind the diet – drastically reducing carbohydrates in favour of a predominantly high-fat, high-protein diet – has become very popular. The best protein powder for weight loss, for example, are low in carbohydrates to fit this no-bread, no-rice, no-carb diet ethos.
However, while the diet is apparently excellent for losing weight, the restrictive nature of this diet could mean it's bad for your heart. One study, published by researchers from the University of Reading (opens in new tab), looked more closely at the relationships between high-fat diets (like the keto diet, which looks to substitute some carbohydrates with fats) and heart health.
The study's results were interesting – and concerning. Based on experiments with mice, it was found a high-fat diet can cause a normally harmless protein to become overactive. This creates lots of stress on our hearts, resulting in "destructive hypertrophy", damaging the muscles that make up the organ.
The study's first author, Dr Sunbal Naureen Bhatti, said: "Our research shows one way in which a high fat diet can cause damage to the muscle cells that make up our hearts.
"We are really just scratching the surface... but our research clearly demonstrates that high fat diets has the potential to cause significant damage to the heart."
This isn't to say the keto diet in inherently bad for you: as previously mentioned, the high-fat, high-protein diet can have enormous benefits when it comes to weight loss and fitness. Overeating carbohydrates is one of the biggest causes of weight gain in the western world, and the restrictive keto diet is a great way to undo some of this damage.
However, this new research indicates these lifestyle changes should be approached with a degree of caution. According to the UK's NHS (opens in new tab), eating too many saturated fats can raise the level of LDL or "bad" cholesterol in your blood, further contributing to heart disease. It's best to opt for healthier sources of fat, such as swapping butter, margarine and vegetable oil for other alternatives, like coconut or olive oil.
If you're looking to increase your fat intake and reduce your carbohydrates, swap your sources of carbs from high-GI, starchy foods like bread and potatoes, to low-GI, high-fibre sources like cruciferous vegetables and whole grain foods. Make sure you consult a doctor or dietician where possible when planning a big, drastic diet switch.
Matt Evans is an experienced health and fitness journalist and News Editor at Fit&Well, covering all things exercise and nutrition on the Fit&Well website. Matt originally discovered exercise through martial arts: he holds a black belt in Karate and remains a keen runner, gym-goer, and infrequent yogi. His top fitness tip? Stretch.
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