There are foods that require more energy to be digested than they contain; just google thermic effect of food… You can call those (eg: high fibre, high water content, etc) foods whatever you like but science is usually difficult to be refuted.
Such a food does not exist except in theory. No food’s thermal effect surpasses that of its energy content. None.
**Celery does not take more calories to digest than it contains. 20% maximum of its calories are expended in digestion.