This is abit of close to the heart topic for me as well. Yes, am trying not to be so paranoid.
But, for me, only have good food around. I take fruit and yoghurt to work with me, and cause of where i work (location) its not easy to get other food, so i have to only eat what i take and that helps. I do have naughty nibbles when i get home thou. But i stay active as i can. Other then the 1st trim when i had m/s i have stayed as active as before, which i think has helped alot. I do water aerobics 3 times a week, I dont play sports, or go for other walks or anything, but, still keep moving on weekends just by doing stuff.
Drink plenty of water to help curb of hunger. Have big drink of water with meals etc, as long as you are still getting your requirements to keep you and bubs healthy, but, just to stop the snacks.
And yeah, sometimes i do feel like Squishee said - i the only overweight person to be preg! Prob started this preg at 10kg overweight. Although according to my BMI - i should weight in at under 74kg i think - but, 80kg is small enough for me.