Atkins diet works simply by 'filling you up'

"[The study] found that although Atkins dieters were allowed to eat as much as they liked, they ate as few calories as those on the low-calorie diets and significantly fewer than they would eat normally.
The findings, the programme suggests, solve the mystery of how the Atkins diet works. 'It might have nothing to do with calories being lost and apparently nothing to do with burning more calories. Neither does it seem to be due to gorging on fats,' it says. Instead, 'protein makes you feel full.'"