It takes some pre-planning. You can still cook some of the same things that you usually make for the rest of the family, but go through your repertoire of meals and make a list of some of the healthier ones, you might want to forego some of the unhealthier ones for awhile.
So with the regular meals, you will simply be adjusting your portion size and eliminating or limiting the additions such as salad dressing, croutons, cheese, butter or margarine, sour cream etc. Maybe you don’t eat a roll, and you don’t have dessert. You should also plan to have a salad with each dinner, but don’t add cheese or croutons or olives, switch to chopped or grated raw veggies and use only a tiny bit of extra virgin olive oil with your favorite vinegar, don’t use any of the bottled dressings, they’re usually loaded with fat, and the fat free ones taste terrible. You can also make a dressing with non-fat yogurt (I can supply you with some recipes).
The other thing you can do, is to alter your recipes, to make them healthier and hope that your family will still like the food. If that doesn’t work, then you will need to plan even more.
If you end up needing to make a separate meal for yourself, work it into the whole meal prep plan. Make a menu for the week, get your supplies ready (ahead of time, so you’re not scrambling at dinner time) prep as much stuff ahead of time as you can.
My Mom has changed her eating habits considerably in the last 2 months, going super healthy, so what I do is go to the store and get all of the fruits and veggies and whole grain breads and tortillas and whatever I need. Either that same day (if I’m not too exhausted by the shopping trip) I will wash and chop the veggies and put them in separate bags, so they’re ready to go when I prepare a meal. I also might prepare a vat of vegetarian chili and freeze some of it. Same thing with soup, so that I can simply pull out one of my frozen containers the night before and have it thawed and ready for the pan or microwave when dinnertime rolls around. You can still prepare whatever other meal you might have been going to make for the rest of the family, but your healthy meal will be much easier to throw together.
Lately I’ve been making lots of salads, like Waldorf salad, tabouli, coleslaw, bean salad, but I use healthier ingredients like non-fat Greek yogurt instead of mayonnaise, or a squirt of lemon juice instead of Italian dressing. Find yourself (or I can help you) some recipes that sound good, that you can make ahead of time, that will last 2 or 3 days, and that will be part of your meal (even if no one else will eat it, like my Dad won’t eat any of this stuff I fix for my Mom)
It’s kind of funny, because on some days my Mom is in the kitchen fixing a pot roast for my Dad (that will last for 3 or 4 days, plus some frozen leftovers) while at the same time, I’m in there prepping veggies and creating salads for her and me.
Pre-planning is the key. And don’t forget to add in a 30 minute walk every day : )