The idea of the LCD is to kick start your metabolism due to the liver being the organ which controls this within your body (for the main part), so I suppose it stands to reason that your metabolism wont work properly again until you've 'cleansed' it enough. Maybe that man had a very unhappy liver?
Eating healthy food definitely makes a difference. Even just the act of getting out of bed is easier for me these days. I don't wake up feeling sluggish anymore which is great and makes it much easier to deal with the daily grind of getting everyone off to school and work.