I’ve tried the Keto diet and will likely try it again. It’s an expensive diet for sure but it does have its benefits. You may disagree but I don’t think it’s healthy to stay on it more than a couple of months (at most) at a time then go back to regular but reduced carb diet for at least a month before returning to Keto for another month or two.
No one really knows for sure so all we can do is gather the info available and make the best educated guess we can at what will work best. No one diet is best for everyone so some trial and error is bound to happen on this journey.
I have found through N=1 that ketosis is not essential for weight loss or maintenance. It can be essential for curing or treating a chronic disease. But for just good metabolism and weight loss or management, you needn’t worry if you are in constant ketosis, because we rely too much for immune work and brain function/moods on our gut bugs. And our gut bugs need natural starchy carbs.
So in my opinion it is best to use your carbs for the day on foods the gut bugs eat. Feel them like the wonderful pets they are. They literally keep our moods good, and fight flu and cancer etc. we need them and they depend on us to feed them.
Without the starches they love, you will end up with populations of less beneficial bacteria. The best ones want resistant starches. So cooked or fermented fibrous veggies, potatoes and rice that has been cooked and cooled (and can be warmed up), all the root veggies, and you can cheat with potato starch and insulin starch for very low carb yet highly functional gut bug food!
Mine are eating granola made from mostly seeds (a serving of maybe 3 tbsp is enough), potatoes (not every day), some kind of fibrous veg, and a tbsp of inulin (Made from Jerusalem artichokes) every day just to cover all bases. If you eat low carb and you are out and have a choice of a green salad or cooked broccoli, your gut bugs are begging you to take the broccoli. The lettuce does NOTHING for them!
And if you eat like this, with 30-70g carbs a day, you will sometimes be in ketosis, sometimes not, and for weight alone, it doesn’t matter.
I just stick to low carb and don't worry about Keto or any other kind of strict diet. Works for me. BTW, if you do couponing, low carb eating is cheap.
I did keto last year and lost 17 pounds in about 4 weeks. I was very strict with myself, and stuck to 20-25 carbs a day. This time, When I went off of it (mostly because I could not find a bread recipe that wasn’t disgusting, and I need a sandwich once in a while). After I went off it, I gained back at least all I had lost, and then some, but then I went back on low carb, not completely strict keto, and I lost so much that I weighed less than when I lost the 17 lbs 8 months ago -— having lost another 9 lbs. And that was with cheating when I go out to eat. I have found some acceptable bread recipes, using carbalose flour, which isn’t as expensive as almond flour. My biggest trick to stave off carbs? Treating myself almost every night, with strawberries sweetened with splenda or stevia, a low carb biscuit (made from carbalose, and about 1/4 cup heavy cream, whipped (to about 1/2 cup, after whipping). In other words, strawberry shortcake. Even when I was on a strict keto, that every night, didn’t keep me from losing weight.