PlanetBox is designed to keep foods from “touching each other.”  When you close your PlanetBox, the top and the bottom meet so that foods will not co-mingle, even when carried and stored on its side.
PlanetBox is not designed to be leak proof.  The lunchbox itself is not air tight and it is not designed to hold wet, messy foods like yogurt, dips, and applesauce.    We created the Big, Little and Tall Dippers to use for foods such as these.  For the larger Launch Box, we also created the glass Satellite Dish.
Here is some information about how to pack messy foods such as fruits:
When packing fruits, the majority work just fine packed directly in your PlanetBox.  In our months of testing we have found that most cut up fruits will not create enough juice for there to be any spilling.  However, some fruits can be rather juicy, especially melons and citrus.  We have found that if you cut and pack these fruits the night before, they can create a lot of juice that can leak if put directly in the PlanetBox.  Therefore, we recommend cutting and packing these fruits in the morning (they make a lot less juice that way) or you can blot the fruit in the morning with a towel to absorb the extra juice. You can also pack them in the Big or Little Dipper (the Rover only), Tall Dipper (Launch or Shuttle only) or the Satellite Dish (the Launch only).