Hack #1 - Eat fewer calories. Your body burns something called calories for energy. However, if you eat more calories than you burn, you will gain weight. Therefore, if you eat less food, you will gain less weight. Read up on calories at wikipedia and you will see what I mean.
Hack #2 - Exercise more. As I mentioned in hack #1, your body burns calories for energy. So, if you exercise more, you will burn more calories and you will lose more weight. I recommend you either run or walk up and down a staircase a few times per day. This will put you on the road to weight loss.
Hack #3 - Drink more water. I don't know why this will help, but people always recommend you drink more water so that you will lose weight and feel more energized. Drinking water is recommended for everything!
Good luck and remember: weight loss is a marathon, not a sprint!