My experience (and that of research on folks that keep the weight off long term) is that the most effective way is to not view the dietary changes as a short term diet. The most effective approach is permanent dietary changes (the basics of good nutrition (lots of fresh veggies, some fresh fruit and healthy protein and healthy fats. The amount of carbs and grains highly variable depending upon your metabolism/body type)
This diet may be good as a kickstart and motivator to lose a larger amount of weight at first (you don't mention a goal and the amount you want to lose relative to what is a "healthy" weight for you makes a big difference as far as how much weight you can lose and how long it would take to get to your "healthy" weight. NOte, that I say "Healthy" weight as we are all different and unfortuantely, in our culture what some folks think is a desireable weight for them may not be healthy. For example, I'm at a very healthy weight right now, but would love to be 10 lbs lighter. Realistically, this isn't logical and indeed if I were 10 lbs lighter, my health might be at risk - body fat is important in maintaining normal hormonal balance.
Also, in my experience, it can take years after the birth of a child for your body to fully recover and for it to be reasonable to get back the figure that you had prior to motherhood. For me, it took 7 years for my hips to get back to pre-childbirth size - our hips do expand as the cartilage loosens to allow that baby to get out!
I know this is lots more info than you wanted. But, this is such a common question on Mamasource. I was a chubby child and tried every diet available at that time for 15 years - 12 to 27. It wasn't until I made permanent dietary changes (removing virtually processed carbs and foods) that I've reached a weight that fluctuates +/- 5 pounds for the most part. I get more strict with myself (eliminating carbs and increasing exercise) when I start moving above that +5 lbs.
I've followed this approach now for 20 years and am basically the same size as I was at 27, which was about 15 lbs lighter than I ever was at 17. I can wear jeans that I wore when I was 16. I keep a pair around for motivation when I "feel" fat. Unfortunately, the self-confidence of women is just so impacted by how we "feel" we look.
One of the most important aspects for me was to find an exercise that I really, really enjoy. I cycle 3-5 times a week (and have for 20 years, even while pregnant) and I walk my dogs every nite for 30 minutes. This has a tremendous impact on how I feel each and every day. Given that you have two girls, I think modeling this behavior is so, so very important.
Also, I don't eat dramatically different than my kids - I have the same protein and veggies with dinner. I just give them a starchy side dish (rice, potatoes or rice pasta). I also don't eat their snacks (a good habit for me is buying their snacks in single servings as much as possible - it limits how much I might have when I just feel I want a "treat").
My husband's side of the family are all overweight - some even obese. We can see that my younger son has those same genes, so we do talk about him likely needing to be very careful about his diet and making sure that he exercises enough (that's no problem for him at age 13, but could well be at 23, which is when his dad really put on the weight. Also, diabetes runs in my husband's family (as well as depression). These things are all connected and all highly impacted by long time lifestyle choices and decisions.
And, again, as well as your losing weight by making the right choices, you will do a wonderful job of preparing your daughters to have a positive self image and dramatically increase their health in a positive manner.
Good luck.