If your goal is to just weight a lot more just eat a lot more and enjoy being a fat boy. Very easy eat at least 10,000 - 15,000 calories a day. Include lots of cake, ice cream, pizza, burgers etc. Eat every hour. Wake yourself up every 2 hours to eat. Eat like a pig and then stuff your face some more. Throw cheese into a blender and drink it up if you have to.
Eat until you are sick and then eat some more. Do not exercise. Burn as few calories as possible while filling yourself up with them. Allow your inferiority complex to drive you to get bigger. Listen to your mind telling you that you are small and weak because you ARE! You are just a skinny little breath of wind that any girls on tinder will laugh at and quickly swipe you away. Little man you could never please a woman unless you gain 10 kgs THEN you will be a real man! Don't worry about being a fat boy with man titts and a tire around your gut in the coming years girls like that. BIGGER IS BETTER BY ANY MEANS POSSIBLE!!!