If people are eating X and you get them to eat <X weight will be lost
(or the body adjusts metabolism downwards). That's basic thermodynamics.

There are simpler and more complex ways to accomplish this.  Complex
approaches involve percentages, rigorous calorie/macronutrient counting
and all of the rest.

This 2PD is obviously a simple approach. These generally work up to a
point and humans, being crafty bastards, frequently find ways to abuse
the system.  Someone could eat 2 lbs of jelly beans a day and not lose
weight but that's hardly what's being suggested.

But, at a fundamental level, both low fat and low carb approaches fall
into the simple category: Since food Y (where Y = fat or carbs)
contributes a lot of calories to the diet (fat because it's calorie
dense, carbs because they typoically make up 50% or more of the total
diet), if you get people to eat less of Y, they will eat less total
calories and lose weight.  There are some ASSumptions (which are more or
less correct) that goes into this but I have to go train and don't have
time for one of my typical long-assed posts.

If you make them aware of how much X was to begin with (X typically
being far larger than most people are aware) all the better.  Weighing
food is a huge pain in the ass but it gives people food awareness and
that's a good thing.

So other than the fact that Mu is an annoying retard troll (standard
troll tactic is to change screennames to avoid killfiling), what exactly
is your problem with the simple concept that 'if you eat less than you
were eating previously, you'll lose weight'?  Because, at its heart,
that's all this 2PD thing is: a fairly simplistic way of getting people
to eat less.

Lyle