OK, I have an intrest in this and here is my 2 cents!

I do still believe in calorie in equaling calories out. What I object to is the focus placed only on the 'calorie in' part, with the tacit assumption that calories out is pretty much constant, with a bit of range for extra exercising.

From my reading and experience I believe that calories out will vary based on a number of factors.
* Exercise - it isn't the calories you burn during the exercise that is signifigant, it is the change it makes to your burning rate more generally.
* muscle/body fat compositoin - we all know this, but it is a SEPERATE EFFECT from that noted above
* sources of (macro)nutrients
- Atkins gives an advantages becuase eating fat and low carbs increases your calories out, not just becuase it tends to reduce calories in. This is why on that study low-carbers could have 300 cals more and lose the same amount of weight.
- I do think that for many the source of extra calories is signifigant. Extra cals from low-carb bars are more likely to upset the balance, then extra cals from other sources that may compensate by increasing calories out. Studies have shown this to be the case with extra calories from moderate nut serves - in the study those with extra calories from nuts maintained weight while those with extra calories from other sources gained.
*The digestive function/ how much stuff your insides are doing
- while 'negative calorie foods' are a bit of a myth, this is the reason studies on the importance of breakfast give. If calories in was the only variable eating an extra 400 calories at breakfast wouldn't do any favours. However, it has been consistently shown that eating earlier increases calories out by speeding metabolism - dieters that eat breakfast lose more even if they eat more calories.

* Your body's response system
- Yes, I think there is ample evidence, both in scientific journals and ancedotal on this site, to support the starvation mode theory.

I think you play with fire lowering calories too much for too long. I admit, I have played in that fire. In the end you need to think if eating 1200 calories is sustainable for the rest of your life, and if it is healthy to be sustaining that.

It is very difficult to get all the vitamins and minerals you NEED at 1200 calories (less then 1800-2000 I would say) at low carb OWL/pre-maintence. Sure, you can rely on your "insurance" of multivitamin just as those who stay on induction for long periods must do -- but I wouldn't want to be stuck at a low level of calories for ever having ****ed up my metabolism.

People who can't go over a fairly low amount of cals without gaining I would consider
* Do I have a history of severe low-calorie dieting and that might be why?
* What am I doing when i go over set number? Extra calories from some macadamias or lower carb yogurt (for those that are in OWL) may be less hurtful then from low carb junk food.

ANd my final 2 cents. I think that 10-12X figure doesn't work as well the further down the scale. During induction, I found 1700-2000 calories a useful guide. Now, I consider 1200-1300 calories a complete joke, and completely unneccessary and unhealthy.