Of course, the energy and calories consumed during treadmill training depend on variables such as weight, gender, treadmill speed, slope, and even the temperature of the training environment. I did not include some debatable variables such as supplements in this list because it complicates the discussion
Of course, you want a quick and methodical answer. If your weight is between 60 and 70 kg and if your treadmill speed is about 7 km/h and with zero inclines, you will probably consume between 250 and 350 kilocalories of energy every hour (Based on estimation).
For every 3500 kilocalories burned if it is not compensated by nutrition, about 450 grams of fat weight will be reduced, which has very little reversibility. During this time, you will lose more weight, which will be caused by the loss of body water.
All the best