The other day, I shared our healthy habits weight loss program and got this comment.
The ketogenic diet, or “keto,” seems to be the latest fad these days for losing weight. There's little doubt that it can work; a quick Google search will bring you tons of success stories. It's not challenging to learn either with courses out there like “Crash Course 2 Keto – Ketosis Made Simple” which are relatively cheap and can teach you everything you need to know in a few hours.
So why don't I recommend keto?
The short answer is it's a diet. And like most diets, it is intended for short term use. There are also some concerns about long term health when it is used for long periods. Keto was not even originally intended for treating obesity, although in more recent years it has been.
Here's what Mayo Clinic (which is where the Ketogenic diet originated) has to say about Keto.
Mayo's verdict: While the ketogenic diet may be recommended for some people with uncontrolled epilepsy, the high fat content — and especially the high level of unhealthy saturated fat — combined with limits on nutrient-rich fruits, veggies and grains is a concern for long-term heart health. 
While it is hard to argue the fact that people have gotten benefits from this, I've also witnessed what happens after someone comes off of keto or any other heavily restricted diet. I've seen a close friend do this, and shortly after quitting keto, she went back to her old habits and gained back even more weight than she took off.
I've seen this over and over with diets. While they may work in the short term, it's easy to fall right back into old habits later, which is how you got to where you were in the first place. Not everyone goes back to their old habits, of course, and I admire people who have gotten their health back through keto or any other program, but many do.
It’s natural for anyone trying to lose weight to want to drop it very quickly. But evidence shows that people who lose weight gradually and steadily (about 1 to 2 pounds per week) are more successful at keeping weight off. Healthy weight loss isn’t just about a “diet.” It's about an ongoing lifestyle that includes long-term changes in daily eating and exercise habits.
On the other hand, you may want to create healthy long term eating and exercise habits and skip keto altogether, which is what I do recommend.
1. Wheless JW. History and origin of the ketogenic diet (PDF). In: Stafstrom CE, Rho JM, editors. Epilepsy and the ketogenic diet. Totowa: Humana Press; 2004. ISBN 1-58829-295-9.
2. The truth behind the most popular diet trends of the moment by Mayo Clinic Staff
3. Losing Weight – CDC
4. Ketogenic Diet for Obesity: Friend or Foe? – National Institutes of Health