Richie
Naybet
I've just explained to you scientifically why what you are saying is not scientific fact. But you're still claiming it is. So, let's look at it from another angle, show me the equation that is used to work out that there are 3500 calories in 1lb of fat.
There are plenty of people who are 17st 10% body fat. Pick any pro rugby team and you'll find a few.
It will only average out as 2lb 'in time' if the person losing the weight has the correct metabolic conditions (as explained in my previous post) for them to lose 2lb per week on a 1000 calorie deficit. As I keep saying, this is not everybody.
I do agree with your last statement about people not re evaluating requirements though.
I don't quite understand your 'metabolic conditions' argument here. The issue is about taking 1000 calories off of your maintenance calories, this takes in to account all factors such as metabolic rate, sex, age, exercise levels etc... Your point about varying conditions is correct, as the person loses weight their metabolism changes and therefore the maintenance calories needs to be adjusted, but this doesn't affect the calories in vs calories out (CICO) argument. Obviously if someone loses 50lbs they will need fewer calories compared to when they were heavier, but these issues are addressed in tandem with CICO and eating at a deficit.
I see your argument about a 17st man at 10% body fat, but that's a straw man IMO. This kind of advice is clearly aimed at the average overweight person in the UK, not professional athletes who are by definition genetic abnormalities. For someone who has a significant amount of fat to lose and minimum muscle the advice is sound IMO, although I would advocate a 500 calorie deficit.
You are likely correct (I don't know the maths) about your calculations on the energy store of fat and muscle, but fat is designed to be an energy store and will be used first assuming the person is active. If someone is 20%+ body fat, eating at a deficit and exercising regularly, the vast majority of their weight loss will be fat and the 2lb/week figure will be roughly correct.