From the Wikipedia entry on William Hope Hodgeson’s 1912 far-future SF novel, The Night Land:
Powdered Water and Food Tablets
Hodgson’s hero sets out into the Night Land carrying lightweight food tablets and a sealed tube full of “water-powder.” When a small quantity of this powder is exposed to air, it absorbs water rapidly from the air, reacting rapidly and producing drinkable water. While lightweight dehydrated foods exist, water-powder is scientifically implausible (though see deliquescence), but together these serve to explain how the hero can carry enough food and drink to survive his journey in the inhospitable Night Land.
Great minds, Bo, great minds.