Here is how I lost 100lbs (45kg or so) a few years ago - I am not a doctor, or a nutritionist, or anything like that. This is just what I did and what worked for me:
For diet-
I cut carbs to below 50g a day. Cut sweets, sodas, candies, sugars, etc.
I stuck between 700 and 1400 calories a day.
Have a cheat day once a week where you eat whatever you want, and how much you want. This helps your body stay in fat burning mode.
Exercise -
I do calisthenics.
Here's how I do them: Find a 3 story or larger staircase. At the top, do 10 pushups off the railing, or some sort of ledge or surface you can use (i.e. low intensity pushup. important to not do regular pushups). Go to the bottom. Do a 30 second wall sit. Go back up, rinse and repeat for an hour and 15 minutes. Do this at least 3 times a week.
I myself now do a 2 minute wall sit at the bottom. As you do the workout more, over time, up the intensity as your endurance increases, to continue getting results.
It's good for burning fat without building much muscle, while upping your endurance.