And some will endlessly argue against “simple physics” because magical thinking about metabolism avoids any hint of personal agency. In a sense, the body isn’t

And some will endlessly argue against “simple physics” because magical thinking about metabolism avoids any hint of personal agency. In a sense, the body isn’t “simple” because so many things can affect your total energy burn. But all of that really doesn’t matter much. If you continually decrease your caloric intake, eventually it will fall below your calorie burn and you will lose weight. Conversely if you continually increase your caloric intake, you will eventually gain weight (assuming you aren’t literally shitting out undigested food).