The current dietary guidelines have basically unchanged since Ancel Keys persuaded the McGovern committee in 1977 that fat would kill you and carbohydrate wouldn't.
Well, we all know where that went - exponential rates of diabesity and obesity for starters, then Altzheimers, stroke, heart disease etc.
So, despite decades of evidence to the contrary, the stubborn intransigence of the powers be insisting their stance is evidence based, we are left wondering who is right. More often than not the message is, the message isn't being adhered to - ie eat less move more and if it doesn't work, it's YOUR FAULT.
Here's a screenshot from a talk by Amber O'Hearn at the KetoCon 2017. It clearly shows that the public HAVE got the message, (yet are still sick and unhappy).
You can see this for yourself in any supermarket. See what's in the basket of anyone overweight or obese (applies to normal weight people as well) Almost invariably you will see ghastly green or pink topped milk together with any amount of low-fat spread, yoghurt, etc. Then there's the new kid on the block, Arla yellow top - "Tastes Like Skimmed" (What in the name of God have they done to it to make it even healthier, whilst maintaining the 'taste'?) You can back this up by looking in the milk cabinet to see how much full-fat blue top is there. Supermarkets won't stock what doesn't sell!
The thinly veiled contempt we are held in by the elite of the diet experts, whose arrogant attitude is one of 'If you weren't such a glutton and a slob...' drives me wild when it's NOT OUR FAULT. If you eat the wrong foods (carbohydrate heavy) your willpower will not be enough to control your 'always hungry appetite.' You are being hijacked by dysfunctional, hormonal signalling; and biology will ALWAYS trump willpower.