▁" cost " ▁of ▁dig est ing ▁the ▁food — w ould ▁be ▁greater ▁than ▁its ▁food ▁energy ▁content . ▁Despite ▁its ▁rec urr ing ▁popular ity ▁in ▁di eting ▁gu ides , ▁there ▁is ▁no ▁scientific ▁evidence ▁supporting ▁the ▁idea ▁that ▁any ▁food ▁is ▁cal or ically ▁negative . ▁While ▁some ▁ch illed ▁be ver ages ▁are ▁cal or ically ▁negative , ▁the ▁effect ▁is ▁minimal ▁and ▁requires ▁drink ing ▁large ▁amounts ▁of ▁water , ▁which ▁can ▁be ▁dangerous , ▁as ▁it ▁can ▁cause ▁water ▁into xic ation . ▁ ▁Cont ro vers y ▁There ▁is ▁no ▁scientific ▁evidence ▁to ▁show ▁that ▁any ▁of ▁these ▁food s ▁have ▁a ▁negative ▁cal or ific ▁impact . ▁Food s ▁claimed ▁to ▁be ▁negative ▁in ▁cal ories ▁are ▁mostly ▁low - cal orie ▁f ruits ▁and ▁veget ables ▁such ▁as ▁cel ery , ▁gra pe f ruit , ▁le mon , ▁l ime , ▁apple , ▁lett uce , ▁bro cc oli , ▁and ▁cab bage . ▁However , ▁cel ery ▁has ▁a ▁therm ic ▁effect ▁of ▁around ▁ 8 %, ▁much ▁less ▁than ▁the ▁ 1 0 0 % ▁or ▁more ▁required ▁for ▁a ▁food ▁to ▁have ▁" negative ▁cal ories ". ▁▁▁▁ ▁Di ets ▁based ▁on ▁negative - cal orie ▁food ▁do ▁not ▁work ▁as ▁advert ised ▁but ▁can ▁lead ▁to ▁weight ▁loss ▁because ▁they ▁satisfy ▁hung er ▁by ▁filling ▁the ▁st om ach ▁with ▁food ▁that ▁is ▁not ▁cal or ically ▁dense . ▁A ▁ 2 0 0 5 ▁study ▁based ▁on