I snack all day long and string my meals out too as I can't scoff anything down fast. But I also ensure that what I eat isn't super calorific high carb foods. IE I'll snack on veggies all day like sugar snap peas, carrots, I like red cabbage & yoghurt dip, beans, and nuts, I also like pomegranates as they take a long time to eat, figs, grapes, gooseberries, and greek plain yoghurt (anything flavoured is usually the same sugar & carb content as chocolate bars) etc.
In my car I have seaweed snacks and I take those for movies. My meals limit carbs to a handful, I have gestational diabetes and I find that the sugar in carby foods doesn't make me feel well. I generally feel puky when I don't have enough protein and too much carb.
Eating carbs packs the weight on for me and makes me feel quite ill with the sugar loads. Protein & veg with some fruit seem to make me feel the best. With my first pregnancy last year I gained 24 pounds and with the twins this year so far I'm nearly 24 weeks and have gained 18 pounds. Protein keeps me satiated too for longer periods of time whereas rice, pasta, grains, breads make me hungry with the constant sugar rollercoaster.