I'm on day two of a radically, (for me), different diet. It started when I went for an initial meeting with my New Primary Care Provider, to get a physical, and was immediately stuck in an ambulance and sent off to the emergency room. My blood pleasure was 250/180!
Anyway to make a long story short, I have terrible lipids, high blood pressure, and overweight (but not quite Obese). Fortunately, all the other blood work, and ekg's are boringly normal. Unfortunately, I can't handle statins, and I would really like to get off my new blood pressure meds as soon as possible.
So I researched various and diets/lifestyles and decided to try "The Paleo Cure" by Chris Kresser. For the first 30 days, you eliminate: all dairy, all grains, all seed and vegetable oils, all "packaged" foods, Legumes (except green beans), processed sugars, artificial sweeteners, and alcohol. Basically the entire calorie consumption of the average American today.
You can eat lots of vegetables, meat (properly raised), eggs, fish (with preference for cold water fish), other seafood, most nuts, Coconut in all it's forms (oil, water, milk, and meat), Olive oil, lard and lots of fruits.
The reason for this first phase is to cleanse your body of modern day poisons, and "reboot" your body. After thirty days you start to introduce some of the "forbidden" foods and evaluate how they affect you. I plan on "testing" butter, fermented dairy, and peanuts first.

I will probably never "test" gluten, as my wife has Celiac Disease, so it is actually easier for both of us to avoid it.
I have chosen to try this route for several reasons:
1. It will make me more resilient, as I can grow, raise, and catch a large portion of my diet.
2. It matches my ethics; care of the earth, care of people, return the surplus.
3. I no longer support financially Monsanto, and other large scale, poison spreading, soil destroying, dead zone creating, carbon producing, companies.
4. I further reduce my carbon footprint and help regenerate the earth.
5. Finally, the science seems sound, and I believe it will work.
We are also concerned with Dementia. We just happened to tune into a great Japanese documentary on the latest research on prevention and even reversing Dementia. The Paleo diet seems compatible with mitigation efforts. However one the most effective treatments seems to be: Keep moving. Especially, include a one hour
CONTINUOUS brisk walk, at least three times per week. We have added this to our routine, even though we are already pretty active.
My goals are to: reduce my BP to the point of going off meds for it, fix my lipids, lose 40 lbs, and prevent Dementia. I'll let you know the results, unless I forget.
Anyway, at worst I'll know one more thing that does not work. At best, it improves my already pretty great life.