Ally,
I don't want to keep going over old ground, but a bit of historical perspective would be good. The genesis of the 'Eat Well Plate' can be traced back to the US 'Dietary Goals for the United States' in 1977. It was this US government funded study which underpinned the infamous 'food pyramid' and all subsequent Western government funded dietary advice since. We have imported it along with our headlong rush into obesity and diabetes.
I agree with you when you say that sugar is the problem, but isn't that an admission that the standard advice from the NHS, to 'base your diet on starchy carbohydrates' supports that problem? Starchy carbs are very quickly metabolised into sugar, are they not? So such a diet, which continually repeats the mantra 'eat less fat' (why do you keep missing that bit!) is inherently higher in sugar and lower in fat. I gave you an example before of a diet on the DUK website which had a ridiculous 12.5% fat and I know from bitter experience that if I were to eat like that for even a few days my weight would increase, I'd need much more insulin, and my blood sugars would be up and down like my 4 year old on a bouncy castle. It's just plain daft.
As you say, the standard dietetic approach seems to be just to hand out a standard 1800 calories, with little recognition that all calories are absolutely NOT equal. There are innumerable clinical studies of dietary restriction trials where intakes as low as 1250 calories per day do not induce successful weight loss or, crucially, normal insulin levels. The so called 'paradoxes' where other trials show much greater success with diets higher in calories, provided those calories come from fat and protein aren't paradoxes at all. They are convincing evidence that obesity and diabetes are, fundamentally, metabolic disorders exaccerbated by the consumption of starches and refined carbohydrates.
I'm sure you do a grand job coaching your patients to ditch the junk and eat proper food, and that's a noble cause. In my darker moments, however, I'd like to see some of the nutritionists who tow the party line have their pancreas switched off for a couple of weeks to see how their ideas actually work out first hand. I think they'd change their minds pretty quickly after that!
All the best,
fergus