Research by University of Sydney, Australia, has discovered that the once- popular fad diet has a serious short term impact on wellbeing.
During a three-day stint on the high-protein, low-carb plan dieters had more deep sleep - 18 per cent compared to 14 per cent on a normal diet.
This is because the high quantity of fat in the body stimulates the release of the hormone cholecystokinin that brings on tiredness.
But while the 15 participants slept more deeply, their sleep was punctuated with frequent waking as the body struggled to break down hard-to-digest foods.
Vivid bad dreams
They also had vivid bad dreams and more of them, with the number of dream recalls rising from 20 per cent on a normal diet to 53 per cent for Atkins dieters.
"Some people didn't remember much about their dreams but they definitely remembered that they were unpleasant," said lead researcher Dr Chin Moi Chow said.
"Others reported being chased or experiencing nasty stresses related to their daily lives".
And things don't appear to get much better once they're out of bed, with dieters far more prone to daytime tiredness, moodiness, irritability, poor concentration and ability to make decisions.
"So that's not good on your work situation or social situation, and if you have a lapse of concentration while you're driving that could be fatal," Dr Chow said.
The Atkins dieters, which were studied, were also suffering from low blood sugar levels and ketosis, a physiological condition similar to chronic starvation.
The Atkins diet was developed by Dr Robert Atkins in the 1970s as a radical departure from prevailing diet theories of the time.
Its huge popularity dwindled in the 1990s when the craze became linked to heart disease.
Dr Chow said her latest results, to be presented to the Australasian Sleep Association Conference in Perth tomorrow, further cemented concern about the diet.
Dr Atkins, who died in 2003, claimed any unpleasantness experienced in the short term would lessen over time but Dr Chow said this had not been tested.