First of all, get "diet" out of your head. It is NOT about a diet, it is about changing the way you eat and exercise.
MODERATION is key. You can eat whatever you want but do it with balance. If you starve your body of nutrients it needs then your body will start saving all the extra weight in order to maintain. Example... use real butter, real mayo just don't use as much.
Drink a lot of water. I drink about 6 bottles of water a day. I LOVE infused water with slices of lemon, apple, grapefruit, berries, etc.. you etc you get the point. You get the nutritional value of the water you need plus added vitamins with the fruits you add to the water.
If you drink sodas, STOP. I do not drink sodas. They have no value to your body at all.
You do not have to go hit the gym an hour or more a day. Walk. It is easy, walk at lunch, walk the dog, walk your children to the park, just walk.
When you sit down to serve yourself eat off of a salad plate. It is smaller, it looks like a full plate. NEVER EVER get seconds.
I do not eat large meals. I might eat 4-6 small meals a day.. Breakfast is usually a protein drink, followed by a fruit/nut snack possibly. Lunch is my largest meal which is usually a sandwich or soup, dinner is lighter and I snack on fruits and nuts.
If you crave a dessert, eat 2 bites and put it away. MODERATION is key as well as movement.
I also drink a probiotic daily. Ya-Kult is the one I prefer with the blue label.
Get on a regular routine of what you eat, how you eat and exercise and you will glide into this routine and be healthier and happier for it.
Good luck