> We're talking about cutting out a food category
> and presumably replacing it with another.
Pretty much, yes, depending on how you categorise foods.
> I don't know of any convincing evidence this
> results in weight loss. Open to information of
> course!
Plenty of evidence exists - where have you already looked?
Atkins - probably the most famous. Tim Ferris - relatively recent. Both good starting points for some large (though in some cases you'll find some insufficiently formal) studies.
The 2014 US film 'Fed Up' goes into some good detail about why this particular food category is bad for you - including a lovely animated graphic about a half hour in.
The actual article (did you read it?) this story points to has a box on p24 that describes this too - the 'a calorie is not a calorie'. That box includes several links to some more scientific research on the subject.
The underlying problem is that the sentiment you've expressed - replacing one food category with another can't possibly be effective at reducing weight / risk of disease, improving well-being, etc - is one that the sugar industry is very happy with, and regrettably is very widely held.
To many people it's intuitive that all energy is equal in terms of what your body does with it. Unfortunately there's no evidence that this is the case, and plenty of evidence that it isn't.
Do some searches on things like 'evidence of weight loss with low-carbohydrate diets' maybe append 'high fat' for some interesting variants.
You'll find some good studies, plus an abundance of anecdotes (blogs basically :) of people who've maintained or increased their raw energy input, while reducing their weight, through dietary changes alone.
