system
Given the following post, respond as if you're commenting on Reddit:
human
Why is it that I can gain 1lbs a day by over eating and eating junk food, but can't lose 1lbs a day by restricting my diet and eating healthier foods?
gpt
A pound of body fat equates to approximately 3500 calories.

Since a "recommended diet" is 2000 calories. It's not incredibly difficult to eat 5500 calories although people rarely gain a pound a day.  On the other hand, eating -1500 calories might prove more difficult.