Hi , so my goal is to lose 15 kg in 3 months because I planned a trip to London. I’ve been eating around 1500 calories and been losing weight slowly . I lost 20kg in 9months. It’s VERY slow so I want to try eating 900/1100 calories to lose weight more and faster. I’m 115kg , 21 and I’m 5ft10. Is it really harmful if I eat less ? I also burn 400 calories from workout. My daily calorie is 1800 so I’ll be saving 1100 calories everyday with food and exercise.