Keto is short for Ketosis - very simple - no sugar, no grain.
This is exactly what I started late in September - down 30 pounds and feel as good as I have in years.
If I were an elite athlete there is no way I would chose this diet...not the case. I am a 55 year old man that got a bit over weight and really my body does not process sugar well. So I moved to a no sugar no grain diet. I follow Vinnie Tortorich on twitter (google #nsng) - he is a bit crewd but really is spot on with what he recommends if you are trying to get to a sustainable weight and and eating program.
Meats - fat content is not an issue
Veggies - most veggies are good - some have a lot of lectins which is a whole additional topic - I have cut lectins out as much as possible also
Fruits - berries and low sugar fruits - juices are for the most part glorified sugar drinks so I don't drink them
Nuts - Almonds, Walnuts, Macadamia Nuts are the best
Legumes - I will eat small amounts of legumes or beans...full once again of lectins - so my chili has no beans
Dairy - I eat full fat dairy everything - extra heavy whipping crème is the bomb in coffee! No reduced fat as your body is fooled by this stuff and in many cases processes it just like sugar.
No artificial sweeteners - NONE, which I love - those are all poison IMO.
Stevia is made from real sugar I use it occasionally.
Very interesting discovery - Tortorich talks about how sugar creates hunger in a vicious cycle - after 10 days of no sugars and no grains I could feel my body change...I felt terrible for about two days and once I got through the Keto-Flu I have never looked back. I crave no sugar. Sat in an Italian place Saturday had veal, cauliflower and roasted veggies and did not crave pasta - Pasta used to be my very favorite carb (along with craft beer).
Alcohol - I drink Bourbon on Ice or Gin/Vodka Topo-Chico and real lime juice (from a lime). I do miss my beer and will have a few when I get to my goal of 210. 10 pounds to go.
This is not adkins in any way stretch or form. No grain...atkins is full of grains and fake sugar.