How to know which diet makes you loose the most weight the fastest? (16 year old girl)

Physiology. To lose weight, one has to eat less calories than they expend. So if you eat, say, 1500 calories per day, & you burn 1600, you will lose weight. If you eat 1700 calories per day, & you burn 1500 you will gain weight. It's as simple as that. No way around this fact. Any diet that works has to use this basic principle. Has to be. This is true at any age in any person or animal. Basic biology.