Dr. Atkins strongly advised people not to weigh every day! The scales can become an addiction and they do not reflect true results because fluid levels vary from day to day, and throughout the day, not always in direct proportion to the amount we eat/drink/excrete/whatever.
Once a week or better still a fortnight is more likely to give a more accurate representation - but we are often addictive personalities and the scale becomes yet another tyrant of our own making lol.