Nick, there are a few zero- and very-low-carbers here; I hope we see responses from some of them. I've been ZC for two years (meat only, plus spices and coffee, and the odd glass of wine here and there), and was VLC for two years before that.

In terms of both health and weight loss, zero carb has been fantastic for me. The reason I went ZC is that I stalled for over a year on VLC at 190ish (I'm 5'6", so not a good weight for me to be stuck at). Kicking plant matter, I dropped all my extra weight within a matter of months, and without working out, either. To my surprise, I also experienced tremendous gains on the health front, especially regarding long-term joint pain that is definitely autoimmune, and probably RA. I also just had my labs done, and the numbers are stellar--my vegetarian doctor was stunned.

Just as a side note, I've been reading Phinney and Volek's new book, The Art and Science of Low-Carbohydrate Living, and I'm finding it a very thorough resource on ketogenic diets. I recommend it to anyone who's interested in or thinking about VLC/ZC.

I ate very low carb and quickly lost what little visceral fat I had. I felt fine.

Going very low carb (VLC) is a ketogenic diet. Google "ketosis" for details. Good place to start is here: http://www.ketotic.org/p/ketosis-basics.html.

The diet shouldn't just be low carbohydrate, but high fat, particularly saturated fat and monounsaturated fat from animal sources like meat, eggs, and dairy (or coconut oil). Also, as always, it's probably a good idea to keep the food quality high: minimize vegetable oils, sugar, and wheat.

There is no such thing as zero carbs. Even veggies and meat have a tad of carb in it. What he has done is gone very low carb, which is not required to eat paleo. Potatoes are a natural healthy high carb paleo food. Some paleos also eat fruit in moderate quantities. If you are attempting to lose weight, some paleo eater find it beneficial to cut fructose consumption and maybe even carb consumption. If you have poor blood sugar control, then very low carb may also be the best route for you. If you work out heavily, some paleo eaters find they do better with more carb or more carb carefully timed with workouts. At the basic level, paleo eating means eating foods similar to what our healthier ancestors ate which typically means cutting out grains and unnatural foods, but does not mean you can't eat carbs at all and the macronutrient profile that works best for each individual seems to vary for each individual. Paleo eating is not an exact rigid diet that is expected to be one size fits all. Just because one paleo eater does well on extremely low carb does not mean all will do equally well. There are general guidelines but within those guidelines, you will have to learn what works best for you as an individual.

And as a side note, 3 or 4 oranges a day does not strike me as particularly balanced. If you are going to eat a bunch of fruit, variety is better. But some paleo eaters feel excessive fructose intake is less healthy, especially if you are not a heavy exerciser or if you have blood sugar control weaknesses. Fructose intake is controversial in the paleo community.

If I go low carb I have to increase fat intake. Without the extra fat it is hard for me to be 100% there.

There are many threads dealing directly with this. The search engine is honestly pretty effective on this site.

I did over three months of eating no plant matter at all. Zero. Prior to going full-on like that however I should mention that I was already very used to VLC and ketosis/fat-burning, not taking in glucose, etc.

I felt lowish energy for a good 2-3 weeks I’d say. Nothing amazingly bad but indeed I didn’t feel the pep I used to.

I did it with the intention of really leaning out – trying to get something like 10-12% bodyfat, really ripped up. It did not work. I maintained my weight. I have to think that caloric intake still matters at that point and it was that I was simply not eating a caloric deficit. I have no issues putting down masses of fat and protein.

In the end I would definitely not recommend it. We all know that carbohydrates are not essential for existing. But who just wants to exist? I’d say that understanding macros like tools in a toolbox is a wise approach: use the carbohydrate in a wise way and go from there.

If you’re just going in to it for an n=1 I applaud you. I certainly don’t think its dangerous for anything less than 3-6 months, assuming you’re healthy and fit now.

I'm "zero carb" but it's not literally zero. Threre are carbs in meat, and in shellfish and in liver. When those of us in the zero carb comnmunity talk about our diet, it's probalby more accurate to speak of "only eating animal products".