Paleo anyone ??

As it's been said, the American diet is based upon carbs, instead of proteins. It's completely backswards…
Ketogenic diets, I prefer to say regimens, are super for reversing insulin resistance (pre-diabetes) but, eventually you will get to the point you will stop weight loss.
Keto relies on healthy fats to replace the energy source (carbs) your body was used to burning. This does not happen over night. It takes commitment and discipline. (remember the goal)
Since Keto is proteins, fats, veggies, and zero carb. You must still remember some veggies are NOT zero carb. Sweet peas, for example. duh.
There are 9 calories to every gram of fat. Choose your fats wisely.
One other thing to keep in mind is Digestion! You/we don't digest our foods like we did when we were younger. I am NOT speaking probiotics. I'm speaking digestive enzymes.
Raw veggies carry there own enzymes which also helps to break-down the proteins and fats.
Avocado is a fat but also carries it's own enzymes.
The moral of the story here is, just like on a good drag car, our diets must work well together.

Things to keep in mind, that always seems to get lost in the whole diet minutia thing...

Your protein, in grams, intake should only be contingent with your activity and muscle/body size. If you're at a desk, all day, 10 -15 grams per meal on average. This will increase with moderate exercise. If you are into heavy weight training 3 days a week. Double that on training days.
There are plenty of Online calculators out there to help in this area.
And, before someone calls foul on protein intake, you CAN digest more than 20 grams at a time with the presence of enzymes carried with the veggies, or supplemented. This is also true when it comes to fats. If the Bile Duct is not healthy, which is supported by salt (that's right, salt), preferably sea salt, you may run into indigestion.
Likewise for calories. Very low cal intake at a desk, necessary if you're digging a ditch. (by hand!)
One other very important thing to burn into memory is: The body will not burn body stores (fat) whenever insulin has been raised by the intake of food. Even longer in the presence of simple carbs like sugars, or breads, etc. Even a friggin carrot or a raisin.
Proteins and healthy fats will keep you feeling full for longer periods of time, which helps you keep from eating too much, or snacking. If you eat say a single piece of grilled chicken breast, you can effectively prolong your satisfaction by adding a few slices of avocado.
And Cortisol. Take time to look this up. If you're in a high stress situation, you will find it mostly impossible to loose wt. Even exercising for more than an hour, unless very low impact, will unnecessarily raise Cortisol.
My personal peeve is the use of BMI as a standard. This is purely bullshit. BMI does not take in account your body make up. If your fingers do not touch when you grasp your own wrist, you have a large bone structure. If they overlap, you're considered small boned (you will also rip through carbs while other will not) If your fingers touch, you're in the middle of the road.
Or consider these silhouettes: BBfatguy.jpg They both weigh the same. Muscle is more dense than fat.
Of coarse, this is just the highlights... much more to it.