Signed in 1840, the Treaty of Waitangi is an agreement between the British Crown and Maori. Around this time, there were 125,000 Maori and about 2000 settlers in New Zealand. Sealers and whalers were the first Europeans settlers, followed by missionaries.
Their male subjects burned 105 calories running, 52 walking; the women, 91 and 43. That is, running burns twice as many net calories per mile as walking. And since you can run two miles in the time it takes to walk one mile, running burns four times as many net calories per hour as walking.
If you burn 300 calories per day walking, then cut 500 calories from your daily intake, you have a deficit of 800 calories per day, or 5,600 calories per week. That adds up to 1.6 pounds per week. At that rate, you'll achieve your goal in a little more than six weeks.