The BBC today ran the story of how Frenchman Pierre Borghi escaped from the Taliban in Afghanistan after losing enough weight to allow him to wriggle free through small window 3m off the ground.
He spent 4 months in a hole by himself – the hole was too small for him to either lie down or sit up. Then one night he saw his chance and made a dash for it. With almost no food inside him, and having hardly moved for months, he managed to walk for about 10 hours to find freedom.
He lost around 25lb (11kg) in the last four months of captivity.
Not a recommended way to lose weight – but if anybody tells you that weight loss requires exercise, and with too few calories your body goes into starvation mode meaning you do not lose weight, remind them of this simple story, and also remind them of all those POWs and other captives who are given only bread and water.