"...don't believe in calorie in/calorie out" - You are confusing ELMM (eat less, move more) with CICO (calories in, calories out). Just because you do not count calories does not mean calories do not count.

The First Law of Thermodynamics is not just a good idea, it's the Law! For more, please see the following - http://paleohacks.com/questions/33298/calorie-in-calories-out/33303#33303

I track, more out of geeky curiosity than for any other reason. I however believe in CICO. Not that one needs to "believe" in something backed by scientific study.

I track calories intermittently, in order to make sure that my "gut feel" of how many calories and where I'm getting them from, is on track and accurate.

A couple of times after not tracking for a while, a week's tracking gives me the huge "uh-huh" moment of "so that's where I've been going wrong!" followed by the obligatory face-palm.

In general I try to eat quality and focus on my feelings of hunger/fulness - but it's nice to vindicate those now and again with some data...or get a gentle reminder that my "gut" leads me astray sometimes.

I also track certain large cook-ups. EG I threw together a big stew of beef, sweet potatoes and veggies on Monday and it was good to get an idea of the total calories as a guide as to whether I should portion into 5, 6 or 7 meals...which can make quite a difference.

I track my calories-in (but not my calories-out).
I have a nice little app on my phone that makes it easy.

I use it to keep an eye on my average daily calories over time (as well as my macronutient ratio). If i need to reduce or increase my lean weight, i will make a conscious adjustment in my calorie intake.

So, i guess that makes me a believer in calories-in/calories-out.

Another thing i may have observed in myself, is that a macronutrient ratio change may require an adjustment in calories. ie. If i up my fat intake percent i may need to reduce my total calorie intake a bit to prevent gaining body fat. I'm not 100% sure of this yet, i would need to test further on myself to correlate.

Edit: just read a related article here http://freetheanimal.com/2012/02/synthesis-low-carb-and-food-rewardpalatability-and-why-calories-count.html
entitled "Low-Carb and Food Reward/Palatability, and Why Calories Count"
It talks a bit about why people who are trying to lose weight are initially successful on a low carb paleo diet, then stall (plateau) after a while.

I log mine, I've found that calories aren't that important, but calories do matter (just to a lesser extent than CW determines). I've lost weight on as much as 3500 quality calories per day, but it is more effective at 2100-2200 quality calories per day.

And I log pretty much everything.

I still track sometimes, but not for calories...for nutrients. Days I fee compelled to eat 'weird' I track to see what vitamins or minerals I was craving, so I can better identify that specific 'I want...something...' feeling next time and address it more directly. And days I feel I ate totally normally I also occasionally check to see if my normal really does cover all the bases.

If I track anything, it's the number of grams of protein I'm eating. That drives the whole thing for me, because I eat the amount of fat that makes the meat and vegetables taste great.

Based on my favorite food choices, I know I won't go extremely low or high on carbs, so it's about protein and the fat that naturally follows the protein.

I'm a former binge-eater, so yes, I track my numbers -- calories, protein, carbs, fat, the works.

I have tried not to, but every time I attempt to cease, my brain thinks, "Yay! Food free-for-all!" and I'll eat well beyond satiety. My hunger/fullness signals are completely wonky, but tracking allows me to see that yes, I have eaten a normal amount of food and allows for me to pause and wait for the "I'm quite satisfied now, thank you," message to be delivered to my brain.

I'm also monitoring my carbohydrates in order to repair my menstrual cycle, as I am now convinced that my excessive mittelschmerz (okay, I confess, I just wanted to use the word "mittelschmerz" in a sentence there) and other mid-cycle woes are related to my carbohydrate intake. Again, without tracking, my brain will be like, "Z0mg! Dark chocolate! Bananas! Must. Have. Moar!"

Also, whenever I /think/ I've overeaten, I panic, and will actually commence an overeating fest in response to that anxiety. It's silly and absurd, and I have no idea why (probably some deep-seated issues not unrelated to my former binge tendencies) so having a compilation of numbers that permit me to acknowledge that I did not overeat makes me feel "safe" and thus staves off any subsequent self-destructive binges.

Plus! Numbers are fun! Huzzah for nerdiness! :D

I'm mostly tracking variety of foods to maximize nutrients, and not worrying about the calories. If I'm hungry, I up the fats content to satisfy myself.

I track mostly for Macro-ratios. If Im eating 2500 cals. one day its mostly because I've eaten more fat/protein. This is usually on my rest days. If Im eating 1700 cals. a day its because Ive upped the carbs (usually workout days).

I usually end up eating less calories on workout days, but my carb intake is higher by 30-50 g. Adding in starches like sweet potatoes/bananas gives me energy and keeps my full. I track to make sure I never (or almost never) go over 100g. My goal is weight loss.

I use the previous day's tracking to adjust accordingly to the current day's activities.

I've worn a Bodymedia armband for the past year to track my calorie output, and I use their website to track what calories I eat. Since starting to eat paleo, I don't care about the numbers so much, but I'm in the habit of tracking these things, and I like to know roughly how many calories I'm averaging per week / month.

Sometimes I track out of curiosity, but I no longer need to track in order to stay on track, if you know what I mean.

Whilst it seems daft to say that calories don't count, this doesn't mean to say they ought to be the primary focus of attention.

In order for them to count, first of all you have to establish what they are counting towards. I assume fat/weight gain/loss is the subject.

Whilst calories certainly are a factor in this area, junk masquering as food, intolerances and lack of other essential nutrients are more important factors in my opinion.

When I made my first forays into this lifestyle/arena (I have never been absolutely strict paleo, rather just informed myself with the concept, among other ideas), I made made massive improvements to my health, appearance and fat percentage primarily by cutting out wheat and table sugar. At the same time my appetite improved, my fear of food disappeared and I started to eat a lot more, incluing plenty of fruit, potatoes and rice.

I am unsure if I can say my calorie intake increased because although I ate more, including starches, I had quit bread, cakes and cola, which must have previously contributed large amounts of empty calories; however, it certainly wasn't necessary to worry about calorie intake in order for me to go from 12 stone to 10 stone.

My instinct on the subject was that I had reduced substances my physiology could no longer handle and increased the nutrient intake required to process the other carbohydrates I was eating. Result - appetite increase, weight loss, massive energy increase, greatly improved appearance.

I do not count calories because they don't seem to matter for me. Tracking calories, the few times I've focused on it, has actually distracted me from more relevant aspects of my life, whether that's toxin avoidance, macronutient ratios/timing, stress, sleep, exercise, etc. I suspect I may be somewhat of an outlier here.

No I don't track, but I'm starting it to see how it goes.

Calories always matter, always have. The concept has just been wrongly applied and abused.

Managing your food intake based on calories alone is crazy. If you are incompetent in managing food any other way, it's one way to do it. Just make sure you have 2,000 calories of twinkies a day, and take notes. You will see.

In practical terms, I think if one knew all there was to know about someone that seeks to lose some weight, for any given length of time (thinking months or weeks) we might say that dieting is macro-driven OR calorie driven.

What does this mean? That means there are times in transition when the macros you pick drive your weight more than the calories, within reason.

Take 2 people of exact weight, 300lb, SAD diets, they need help. One eats 2,200 calories in twinkies for 3 months. One eats Low carb Paleo, same calories. What do they look like at the end relative to each other? What mattered more, the match in calories or what they ate?