Hey all! First and foremost, it’s good to be back! I did Keto for about 6 months almost a year ago and had great success. I had lost a great deal of weight and felt amazing. And around week 3, I could tell I had become fat adapted- as my hunger decreased, could fast longer and my energy was through the roof, slept better, all that good stuff! Slowly I found myself straying away from this way of eating and gained the weight back. I have decided I want to start again because as mentioned above, I had a great outcome. However, this time around I am finding myself to have great difficulty even producing ketones. I am tracking my macros, reaching them accordingly, and I know that a week is not anything, but over this short time I have gained almost 5lbs. What gives? Is getting into ketosis harder the second time around? This is nothing like before. I remember reading something about being insulin resistant and your body will hold on for as long as possible, then let go (or something to that effect). I have no desire to stop because I know how wonderful this way of eating is for you body, and frankly I enjoy it. Any advice, tips or just a “hang in there, girl. I have had the same issue.” would greatly be appreciated!!
Back to Keto -- Gaining Weight
Welcome back Heather.
I’ve read that a lot of people find that achieving ketosis the second time around is more difficult than the first… but it’s not impossible. My takeaway is that you have to really buckle down on your carbs and try to avoid keto indulgences, especially artificial sweeteners. I would just focus on single item whole foods and keep carbs as low as you can.
This article by Dr. Michael Eades might give you some insight:
https://proteinpower.com/drmike/2009/01/16/why-is-low-carb-harder-the-second-time-around/
I think it really depends on how fat adapted you are.
I took a small break last week unintentionally, I ate all the things, overloaded on carbs over multiple days. I reached Ketosis within 36 hours, with no fasting required.
Just jump back on that horse and keep going 
Hang in there!
Not myself but my husband has been following a closely ketogenic lifestyle/diet for 10+ years before keto was a thing. This is not going to help you because it’s the opposite of what you seem to be experiencing. There certainly was a period where he went off track and then got back in the saddle again. For him the second time around was intense rapid weight loss and he even lost drastic amounts of muscle (it just dropped right off of him) and not understanding at the time, I was very concerned about his health. After some tweaking, he’s got to a point where he’s comfortable and stable (also back to building muscle).
You didn’t mention how long you’ve been eating/living keto now this second time around (only that you’ve gained 5 lbs). Or did I read that correctly…it’s only been a week? Also what are your meals like? Are you watching your calories too closely and consuming hidden carbs/sugars or too many carby veggies? If it’s only been a week, stick with it and see where you are in 2-3 months.
Its useful to empty ur liver n muscles (with 1-1.5hrs of exercise) off glucose on first day to kickstart ketosis. I remember my 2nd time after a long pause into ketosis i had unusually long ketoflu but never had trouble getting into ketosis.