Now that's something new, someone who wants to gain weight. Well it depends on people, some people take longer to react to it.
But don't eat too much food like all of a sudden, your body might not be able to take it and eating too much food isn't exactly the solution.
Basically it's better to gain muscles than plain fats so just work out and don't go into big exhausting workouts if you are not used to it, like I said, not healthy nor good for heart...slowly build up to it.
Eh, may take a while. But it's a good while, worth taking?
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History Lesson:
Me: "Why do we need so many sources?"
Friend: "To go with our french fries?"