This chapter of the Breathedge guide contains information on renewing health and thirst bars.
In Breathedge, you will not survive long in space without food and drinks. Fortunately, their levels fall slowly, and you will find food almost everywhere. You can produce them and find them in numerous parts of the crashed spaceship.
The main source of food are food packages. You'll make them from nutritious goo and ice. Water can be obtained from two units of ice. You'll find both ingredients levitating around your first base.
In more difficult terrain, you can get ice by destroying asteroids. They have a lot of stamina, though. Food packages can be found also along the way. It is worth to get at least one to know their blueprint. They may contain ingredients that are not necessarily popular, such as honey. You will not have to produce food often - the level of hunger decreases slowly, and you will find various food and drink packages along the way.