My friend every morning takes a pretty brisk walk? is she getting thin? best answer?

Okey so i am asking this for my friend, every morning she takes a pretty brisk walk at 7 in the morning on the streets in the residential area till abt 7:35 and she told me to accompany her. So anyways we walk and when we come back she has a bowl of cereal (cheereos) and a Tangerine thats a her breakfast for the day it before 8'o'clock. And then she hardly eats anything during the day and have supper at 07:00. so she told me to ask will she lose weight?