Your trainer advises you to reduce your calorie intake to between 200 and 500 calories per day? [0] That sounds very, very hazardous for anything other than very short term use, and (given the body's inbuilt "starvation mode") probably counterproductive, even then.
[0] Note that the robot suggested to reduce calorie intake by 1,500->1,800 calories, and the recommended calorie intake is 2,000.
People losing weight are probably eating more than 2000 per day to begin with. But if you go from 2800 down to 1500 you’re already likely to exceed 3 lbs of weight loss per week that is recommended without doctor supervision. If you need to lose more than 150 lbs in a year because you’re well past morbid obesity then you need staff, not just a food plan.
[0] Note that the robot suggested to reduce calorie intake by 1,500->1,800 calories, and the recommended calorie intake is 2,000.