There is too much unwarranted emphasis on ketosis when it comes to Keto diets, rather than hunger satiation. That might sound like a weird claim since the diet is named after ketosis, but when it comes to the efficacy of the Keto diet for weight loss with no regard to potential health or cognitive effects, ketosis has little to do with weight loss. Most attempts to explain the Keto diet almost always starts with an explanation on what ketosis is with an emphasis on attaining ketosis rather than hunger satiation and caloric deficit. Here is intro excerpt from reddit's r/keto:

A Ketogenic Diet is any diet that causes ketones to be produced by the liver, shifting the body’s metabolism away from glucose towards fat utilization. Typically on a moderate to high carb diet, the body will prefer glucose for fuel (usually from dietary carbs), but by restricting carbs, the body will prefer fat for fuel. By inducing ketosis, a series of adaptations will take place.

Even on Lesswrong, discussions of keto, again puts too much emphasis on ketosis. Here is an top level comment in the solved problems repository:

As far as I can tell, ketogenic diets solve the problem of fat loss. I know, anecdotes are not data, but it's worked wonders for everyone I know who's tried it (myself included).

Err on the side of posting solutions which may not be universal but are still likely to be helpful to many people.

This is the sole reason I'm posting this. Keto works for very many people. The short story of keto is that your brain can only eat certain kinds of chemicals. Glycogen from eating carbohydrates is one of them. Ketones generated from fat is another. Your body will preferentially use the first over the second, since turning fat into ketones is expensive. So if you eat few enough carbs (<30g per day is the figure I remember) and plenty enough fat (2:1 fat to protein is what I heard), your body will eventually start doing chemistry that turns dietary and body fat into ketones.

There's some more practical advice about how to induce ketosis quickly (muscles store glycogen, so exercise helps) and how to make low-carb versions of foods you enjoy, but that's pretty much the gist of it.

The vast majority of people on the keto diet and losing weight are also eating less calories and feeling fuller, regardless if the body is going through ketosis or not. To the credit of r/keto there are many there that recognize the keto diet for what it is, but there is still a schism between those that see keto as a neat little hack to eat less, and those that see ketosis as the goal. In short, baring any health benefits of macro composition of your diet, ketosis in and of itself is not necessary to lose weight.

For the vast majority of people's physiology and physique goals, the most efficient thing to do is to find ways for you to best eat less and feel full. Some people use keto, some use intermittent fasting, some use both. I find that intermittent fasting is the least bullshity diet and most honest about how it works – restricted feeding times leads to less chances of over eating, long fasting times decrease hunger pangs, and satisfaction of full "stuffed" feeling of satiety.

Edit: Not bashing Keto, just wished people would focus more on health benefits of keto and efficacy of high protein diets to keep one satiated, rather than an emphasis on ketosis in and of itself.

http://examine.com/faq/what-should-i-eat-for-weight-loss.html#ref3