In a study published in The American Journal of Clinical Nutrition experts from the University of Aberdeen  suggest that low-carb/high-protein diets  may increase your risk of colon cancer.

The study does not bode well for diets such as Atkins or Dukan, which restrict carbs but encourage loads of protein.

The study is on a very small scale, having involved only 17 people who each followed three short-term diets which allowed 360g, 181g and 22g of carbs per day respectively. After four weeks, those on the two diets with the lowest amount of carbs allowed were found to have higher levels of substances called N-nitroso compounds, which have been linked to cancer.

The key, say the scientists, is fibre. If you eat lots of protein and very little carbs, it’s likely that you won’t be getting enough fibre, which is thought to protect against colon cancer. As a result the experts claim people should be wary about eating too much protein and too little fibre in the long term.

This is just another study which points to how unhealthy these high protein/low carb diets are. Protein expert Gail Butterfield, PhD, RD, is a director of Nutrition Studies at the Palo Alto Veterans’ Administration Medical Center and nutrition lecturer at Stanford University.

She says that “A diet in which protein makes up more than 30% of your caloric intake causes a buildup of toxic ketones. So-called ketogenic diets can thrust your kidneys into overdrive in order to flush these ketones from your body. As your kidneys rid your body of these toxic ketones, you can lose a significant amount of water, which puts you at risk of dehydration, particularly if you exercise heavily.

That water loss often shows up on the scale as weight loss. But along with losing water, you lose muscle mass and bone calcium. The dehydration also strains your kidneys and puts stress on your heart. And dehydration from a ketogenic diet can make you feel weak and dizzy, give you bad breath, or lead to other problems.”