I should note that the KG -KM Ratio Estimate was first made aware to me by Radu Antoniu in his video Cardio for Fat Loss. In it he states, "for every km you walk you burn your body weight in kg ... approximately." I tried to find the best article I could to show similiar data for it.
Cardio for Fat Loss
by Radu Antoniu
How many calories do we burn walking 1 km?
Answer by Padmanabhan Mahadevan
Calories Burned While Running and Walking
by C. D. Chester