A leading cardiologist, Dr. Kim Williams has said no one should be doing a ketogenic diet unless weight loss is more important than their health.

Dr. Kim Williams, the past President of the American College of Cardiology, made these comments about the diet – which involves eating large amounts of fat and very few carbs, in a bid to get the body into ketosis (a state where it is burning fat for energy when it doesn’t have enough carbohydrates to burn).

Fans of the diet tout its ability to aid weight loss and improve certain markers around the cardiovascular disease. But Dr. Williams believes the benefits are limited.

Dr. Williams said: “I like the basic concept that you change your dietary habits and you change something. You can make a change, you can discipline yourself.

“Unfortunately, the science of it is wrong. If all you wanted was short-term weight loss – and short-term could be a year or two – if that’s all you’re looking for, great.”

Dr. WIlliams agreed that there are other markers that a keto diet can improve in the short term, then added: “But are any of them independent of the weight loss? Probably not. If you lose a lot of belly fat, your insulin sensitivity improves, your blood sugar improves…it sounds and looks wonderful.”

He added: “There’s only one slight problem: and that’s cardiovascular events. If you look at mortality – I remember pulling out the slide from 2007, that’s the first one I saw, large randomized trial, looking at the ketogenic diet and showing that it increased mortality by about 22 percent.

“So I was talking about that and making sure everyone was hearing about that, and then there was one the Journal of the American Heart Association published a few years later that isolated the people who had had a heart attack in the past, the cardiology population that we’re seeing, and they were doing a ketogenic diet. It was a 53 percent increase in mortality. No one should be doing this.

“Don’t limit yourself to these two trials – take every trial that’s ever been published across the world, do a meta-analysis, I think they had 13 or 16 trials in it, and average them all out…and the answer was 31 percent increase in mortality. So it’s not something people should do unless your weight loss is more important than your life.”