Answer
$\Delta m=+0.087\ kg/month$
Work Step by Step
From tables 4-1 and 4-2:
Energy content of an apple: 70 Cal,
Energy content of 100ml of ice-cream: 110 Cal, hence for 200ml: 220 Cal
Energy consumption for a 68kg person walking: 432 Cal/h, so for 60kg: 381.18 Cal/h
For 20 min of jogging:
$\Delta E= (220-70)-381.18\times 1/3\ h = 22.94\ Cal/day=688.2\ Cal/month$
Assuming the mass change would occur entirely in the fat tissue ($e=33.1MJ/kg$):
$\Delta m=\Delta E/e $
$\Delta m=+0.087\ kg/month$
