We will be going for ten days. Our hotel has a full kitchen and I've found a whole foods nearby, and bought some Lara bars in bulk (better than Mickey bars, I figure!)

We will be focusing a lot on fruit, veggies and meat...

Any tips?

I would take sturdy fruit that will hold up in a backpack- apples, oranges.......
Definitely bring a water bottle- i'd imagine water for a family of 4 gets $$$ at Disney
Of course, eat a good breakfast like eggs- and that way you can enjoy the parks without getting too hungry before a nice dinner.

not the advice you were looking for- but I highly recommend the universal park "The 7 islands of adventure." each island has its own theme- like there is dr.suess land where they even sell green eggs and ham! And in comic book land, if you walk under the cardboard cut out looking cloud, it rains on you. It is really fun!

As a Florida resident I can get a highly discounted annual pass to Disney World and have been there several times with my son, DiL and grandson. My grandson was 2 at the time and we had a stroller for him, and we loaded the back with water bottles which we had frozen in the hotel the night before and a small individual cooler with some fruit, cheese. I added some canned sardines. Even if you don't have a toddler they have strollers available at the park, and it's an easier way to carry things around than in backpacks and shoulder bags!

Not to mention that it's really quite easy to eat LC at Disney if you are mindful. Burgers are available, just skip the bun. Each theme park seems to sell smoked turkey legs at some location, a very popular choice!

We stayed at a nice condo called the Blue Heron Resort that had a full kitchen, but my DiL didnt want to bother cooking and making a big mess. Dinners were things like rotisserie chicken and bagged salads. We bought pre-boiled eggs at the supermarket to give us a start for breakfast. They actually had Larabars for my grandson but I won't touch them since they are so ultra-high-carb. But he liked them. I actually did bring a few Quest bars with me in my purse "just in case".

We had lots of fun and I found it super easy to stay *mostly* LC. I did have an ice cream bar one day. Ice cream has always been a huge weakness for me.

I'm not super low carb, I'm paleo. Lara bars are fair game, at least for vacation!

They sell fruit at different stands in the parks.
I always look up the menus on allears.net before we plan a sit down
meal and most quick service places have salads available and can switch out a dessert
for fruit if you ask. I just pick around a mostly Paleo meal and buy extra fruit or veg later on if I see something I want.
What I love about Disney is that they want to accomodate you
and if you call ahead to any restaurant reservation you have- they can
make you something special- have chef come out and check with you etc.
Just have fun and don't worry there is always something you can eat at most
places in the World.
allears.net is a great resource for where to find what foods at each resort or park