You are now adult, know your body and your usual routines. If your wish really lose weight, your food can work for you. Well, take a moment for think... Are you sedentary or active? Do you have a desk job? How many calories really need for today?
Portion size is important! This is not about be hungry and unhappy, this is for respect your body and work for give you the necessary for be a happy person. If you reduce your portions, I am sure that finally you will burn more calories that you eat. One big salad with fresh veggies without commercial dressing is perfect. Later, eat a little portion of other HEALTHY food that you like :)
Now, I will share with you this article from BBC, with more details for help you :)
http://www.bbc.com/news/health-34246119
Have a nice day!!! :*