I started Paleo sometime in June and have recently talked it over with my boyfriend, who tried it for about two months and kind of gave up. The difference is, I took my friend's advice (He was the person who had introduced me to Paleo in the first place) and went "strict Paleo" for a week, whereas my boyfriend followed the advice here, which essentially says if you're not willing to commit to the diet yet, go at it for two days out of the week and keep going until you're used to it (Or at least, that's the way he took it.)
I felt immediately better after my first week, but he told me that he kept feeling more tired/out of it, etc throughout the months and just gave up on it because he didn't think it was working, and was in fact being counterproductive to his lifestyle. Could this have been because he didn't start it the way I did? Or is it because of something else? I ask because he would like to try it again, but he is skeptical about it working because of what happened the first time he tried.
I am lethargic, dizzy, and week a month into Paleo. I am pretty strict, but I recently cut out all my fruit. I'm told this is common. People on here can explain it better, but it's a transition period and will eventually pass if you keep at it.
2-3 weeks, and honestly, low carb to start out and I think you'll have an easier transition to burning fats over carbs.
I usually have day where I'll eat a few carbs, but stay VLC for the week. I tend to only have about 1/2 a day of carb flu when I switch back now.
The lethargy may be due to low blood sugar, especially if he's working out. I experienced this myself after several months of VLC Paleo when I began a strength training program. The first 2 weeks of the program were miserable. I got very little sleep, I had a constant, dull headache, and I just felt a general malaise all the time. I added about 100-150g carbs PWO in the form of baked or steamed yam/sweet potato or russet potato, that being pretty much all my carbs for the day, and it solved the problem within 3 days. On non-workout days, it's pretty much back to VLC. I've been doing that ever since, and I haven't had any recurrences. In fact, I sleep even better now than when I wasn't working out and did VLC every day. Go figure!
Over and over we see the same complaint...no energy, lethargy, headaches, etc.
Dr Mike Eadtes, author of Protein Power, pretty well sums it up: http://www.proteinpower.com/drmike/uncategorized/lt-frederick-schwatka-and-low-carb-adaptation/
Just have to let the body adapt to burning fats instead of wheat and sugar.
And I will add that the the newby has to eat more fat that they ever thought they could to replaced the lost energy from not eating wheat, sugar and the industrial oils.
As everyone says, it will pass.