Keep a food diary for a few days, don't increase your eating immediately. See where you can add more calories to each meal and where you have time for a few big snacks. Remember it's not bingeing that make people huge, it's just eating more food in a more sustained fashion.
That being said, bingeing can help a little. And another thing that can really boost your calorie count is making your own custom weight gain shakes. Just take things you like and mix them together to make a rich, thick, fattening masterpiece. For instance, I prefer a shake made with vanilla or chocolate ice cream with a half packet of pudding mix, whipped cream, a generous portion of peanut butter, and of course made with heavy cream or half'n'half.
The key to success here is to make your own plan though, something that worked for someone else might not work for you so you'll have to experiment a little. *again the food diary is helpful here if you pair it with a gaining chart, this way you'll be able to see the effectiveness of your diet changes*
12 years
