So I have been very pretty good in ketosis lately doing about 25 g/day carbs. However I am worried about the potential dangers of being in ketosis constantly, so I have decided on periodic carb re-feeds. I currently eat broccoli and cauliflower on my low carb days, and was considering adding half a sweet potato one day per week to throw me out of ketosis for a bit.
Is this a good idea? Is once per week enough or should I be eating more carbs? Any other thoughts on ketogenic diets, will it lead to longevity or is it just a means to lose weight and get leaner?
By the way, the rest of my calories come from fatty meat (beef/lamb) plus coconut oil and ghee.
As far as dangers, you are probably confusing dietary ketosis with the extremely dangerous condition of ketoacidosis. Check out this article for a summary of the differences: http://ketodietplans.com/faq/ketosis-vs-ketoacidosis/ There are no dangers associated with being in a state of dietary ketosis. Just make sure you are drinking lots of water as dehydration can occur more easily. As far as carbing up, if you're overall goal is merely weight loss, it isn't really necessary. However, if you are trying to improve your overall physique while losing body fat, I highly suggest you use a weight lifting routine coupled with a cyclical ketogenic diet (this includes about a day and a half of high carb each week). This is by far the most effective way to lose body fat while improving physique and maintaining muscle mass.
What dangers are you worried about? Are you diabetic? If not, there's no "dangers". Plenty of people live in ketosis for extended periods of time with no problems healthwise. However, it can affect athletic recovery (thus the cyclic ketogenic diets). Longevitywise, it's good to reduce creation of AGE's (advanced glycation end products) in the body by reducing the amount of sugars you consume. Note, not the sole solution, but one of them since you can consume AGE's as well as create them in the body.
experiments are a good thing. a half a sweet potato might not even throw you out of ketosis, though. if you actually want to fill up glycogen stores, you'll need a lot more than that.
i don't think ketogenic diets lead to longevity (disclaimer: i have no interest in extreme longevity), and i don't think they necessarily lead to weight loss either. if they help you eat less and feel better, go for it. experiments are a good thing.
You should check out the book, "The Art and Science of Low Carbohydrate Performance" by Volek and Phinney. They provide great explanations to the benefits of being in nutritional ketosis, and the fact that there are no studies out there showing any long term detriments.
If you're really curious about how ketotic you are, you can try using ketone strips that measure your blood levels. It's a good way to tell if you are in the nutritional ketotic range 0.5-3 mmol. Any higher would yield diminishing returns, with toxic levels being greater than 10 mmol.
I'm currently doing my own experiment with a ketogenic diet and have been measuring my blood ketone levels and blood sugars in the AM and PM.
If you're curious you can check it out at at bjjcaveman.com