I found this post very helpful re fat adaption vs ketosis.
Advice re fasting/ keto/ atkins/ mood?
I’m curious what exactly you ate on atkins. There are several versions of the atkins diet. When I Did it a while ago people recomended a specific publication of the atkins diet book due to them having changed a bunch of things after the death of atkins. Their bars and such were also full of malitol at the time (I don’t know if they still are). If you tried it around that time or ate a lot of their products it’s possible that was part the issue.
Wondering if you need to lower protein and increase fat. Just based on various podcasts over past year. Can’t list any specifically…sorry.
I don’t find it that odd at all - WAY different body processes happen during fasting vs when you’re eating. I feel like a friggin superhero when I fast. 
While you’re eating low carb, are you also eating high fat? How’s your electrolyte intake?
While everyone is different, I would never recommend processed foods for anyone interested in staying in ketosis. Chances are you reach ketosis just fine during your fast, but those Atkins products are not clean. Anything with preservatives, artificial sweeteners, sucralose, starches, modified food starch, cane sugars or syrups is not strictly ketogenic. Hidden carbs are most likely your problem. Something that stimulates insulin and you don’t even know about it. Prepare your own food. There are so many awesome websites and places to get keto recipes.
I hope this was helpful
Keep calm and keto on
Sample menu for a day? Maybe we can help. Also unless you’re pretty active, I kind of think 80 grams of protein might be a bit high. TBH, there are folks who think you should eat more and others who think you should eat less than the macro calculators tell you. Let’s just say - if you’re going by what they tell you and you’re not feeling great, you may have to change something. Make sure your electrolytes (esp. SALT) are plentiful; eat fat to satiety; give it a little time, and change one thing at a time to see what works for you. I hate to say this with the late winter storms hammering us right now in the US, but “we are all special snowflakes.” You just have to fiddle with it to get the right formula for you.
Hey 
Thank you all for the answers!
I couldn’t reply sooner, cos I got a message that I had “exceeded the maximum number of allowed posts on the first day of registering for the forum” hahaha. Yup, I’m a blabber mouth 
Anyway, it gave me lots of time to read up on all the excellent links you posted and I’ve worked out what was going on now re the difference between fasting and LC.
When I started fasting 10 years ago, I was super daunted by it and researched it heaps and talked to lots of ppl about it and read books, websites etc… Once I’d been fasting so well and easily and happily for 6 or 7 years, I guess I got over-confident and thought “Hah, how hard can LC be if I’m a pro at fasting…?!”
But this week, I’ve realised that LC is actually more difficult and more complicated than fasting!
So when I went and just “tried” LC a few years ago, I wasn’t actually keeping my carbs low enough - I was going out of ketosis, which is why it felt so crap. I was in the 50 - 150 g carb bracket, where you’re not keto, but also getting too few carbs for your brain to be running happily on them.
I was exactly in the crappy in-between state.
Sooooo… Now that I’ve worked that out, I’m eating LC (as good as a novice can) and have been back in ketosis for the past 36 hours and am feeling great again.
I’m a bit daunted by the LC prospect now that I’ve understood it!!! 
I’m a vegetarian, tho willing to eat fish as a way of making keto workable… So getting the protein and fats from vegetarian sources makes keto more daunting/ complicated, but I am gonna try.
Thank you sooooooo much for your patient advice and helping me work out “what’s what”.
I have 2 more newbie questions, if I may… What’s “WOE” and what’s “n=1” about?
Thanks!! 
WoE = way of eating.
N=1 means we are all a little different and once you’ve applied the basic rules that work for everyone, you will likely need to tweak your approach as you go along in order to continue to heal (and lose weight). This forum is a great place to find ideas for those tweaks. What works for one person, doesn’t necessarily work for all. This idea is sometimes expressed by saying “we are all snowflakes”.
How is your salt intake? If it is low, maybe this meh feeling is more like carb flu and you should take some broth or boullion to sort that for the first week or so.
Ah LOL…this is the first thing I thought when reading original post - in ketosis = happy brain/ LC (but not enough) out of ketosis = sad brain.
I deal with similar issues and realized very quickly when I started this WOE that it was the ketones that made the difference in my mood. I’m just now starting my comeback after a post birthday lapse
. I was out of ketosis and feeling terrible, jumped into an emergency fast and was back in ketosis within 24 hrs. The effect was dramatic.
I’m going to continue to monitor my blood ketones more regularly to determine my net carb range. I think I’ve probably gone through several cycles of carb creep which knocked me out of ketosis, ignited mood issues, increased carbage and around we go. I also prefer to eat some vegetarian/vegan meals and lots of vegetables. I can do this with clean vegan protein powder, tofu, eggs and cheese.
I’m excited to see more research into ketones and brain health 
N represents the number of test subjects in a study. In general the greater the number of subjects the more relevant the results. But with respect to diet/nutrition do you want to be eating what is statistically best for a large group of people or do you want to eat what is best for yourself? We each can conduct our own n=1 study to try and find what is right for ourselves.
Thanks 
Yeah, I can remember n=1 from uni but couldn’t work out what it meant here.
I love how it’s used here!! It’s great that everyone is encouraged to find what works for them. That’s an amazingly supportive atmosphere. 