I am a vegetarian while the guys in my house aren't (husband, dad, brother/16), so I do tend to eat differently, and that actually leads to portion controlled food. I select the portion of protein and sometimes side dishes that I want ahead of time. Some things we eat together. I always choose more vegetables (the rule in my house is, whatever veggies you cook, expect me to eat half, and you guys split the rest).

They are getting better on their diet in general - and I have been more abrupt with the portion control on self-service items like noodles and salad dressing (getting out the measuring spoon or cup and saying "this is a serving"). Instead of making 6 servings of something, make 3 and make it stretch; make exactly the portion you need to eat and measure it out, etc. My brother and I can afford to eat more because we're more active, but I still measure all of my calories and read every package (or look it up online) and provide statistics that may or may not be welcome to everyone else (stuff like "each tortilla is 200 calories and you just ate 3" ).

It does help when everyone eats the same food and the same portions. I try to add to the middle of my day in snacks and inbetween meals so that shared meals are perceived equal in size to other members of the house (it's easier than doing the math for everyone, I have enough trouble doing it for myself and offering general "advice" to everyone else).