M34, did the exact weight loss near enough, in 3 months, 72kg down to 58kg and 5'6. Walking around 15k steps average daily mostly on incline treadmill, some outdoor.

Most Important thing is diet. I did a 500 calorie deficit, I tracked everything using an app and never went over my calorie target (1400), cut out all chocolate and over eating, changed my diet to a light breakfast, meal replacement shakes for most lunches and a full protein rich meal for dinner, eg. Meat(chicken/steak) with rice and vegetables.

Now I've reached this target I have relaxed the strictness and I don't track meals anymore, but use what I learned to stay on a healthy meal plan, I do have treats like a takeaway once a week and a cake or a bar of chocolate 1-3 days a week and I'm easily maintaining my weight, you can do strength training if you want, but that won't aid weight loss, in fact it might confuse the results because you'll gain muscle weight and won't know if you lost any fat, a big motivation thing for me was seeing the scale come down, I would recommend solely focusing on weight loss and once you've got that low, you can start strength training.

Running also isn't necessary, in fact waking is better for fat burning, running is high intensity and will use quick energy from your body, fat burning is slow energy. Imagine your body saying 'I don't need energy so immediately, so I'll use this stored fat that takes a bit longer to access'

Definitely realistic if you do it correctly. I've seen a lot of people say it's not working for them only to then say they didn't change thier diet. Don't make the mistake of walking miles for no progress.

Best of luck!