"the occasional cake is what we consider good habits."
The only thing we are disagreeing on is our interpretation of 'occasional'.
Timewasting. I have never claimed to be a food expert. I happen to know a bit about it because, as I mentioned earlier, I have a high metabolism and there have been times in my life when I have needed to put on weight and I know that there are healthy foods that allow you to do this - hence me pointing out alternative sources than cake! I am always happy to learn more - including the fact that we don't actually have to eat saturated fat because our bodies can produce it. It was actually a doctor that told me that we DID need to back in university days when I was a vegetarian and not eating much dairy either. This was over 10 years ago though so perhaps recommendations were different then?
We don't each much processed food (Again we may differ on what we consider 'processed' here - bread etc?) and we only eat fish a couple of times a week. I had a dairy intolerance as a child so grew up without drinking milk or eating dairy products - hence doctor's (obviously misplaced!) concern about me in university. The boys seem to have inherited this so they don't drink milk either and only have cheese and yoghurt occasionally too. When I was pointing out alternative sources of fat/high energy foods earlier I included them because MOST people do eat them regularly. I was trying to show that they already have them in their diet without having to eat sweets etc...
I'm really not sure what you consider 'one-dimensional' about my understanding. In any case, you have re-affirmed my point about people eating too much saturated fat by pointing out that we don't actually need to consume any. My point stands from earlier - if you have to limit your intake of saturated fat - what is it better to cut out? Meat, dairy or cake/chocolate? Most people will eat those things every day which is clearly too much. So if you eat lots of what is not actually that good for you how exactly does that make a healthy diet?I bet the majority of people actually eat more meat and dairy than they do fruit, veg, wholegrain and legumes and then put cake and other 'treats' on top of that.
I find it sad that so many people seem to associate joy and pleasure with unhealthy food. Yes, of course it is enjoyable but I also get a lot of enjoyment out of healthy food. I love fruit, I love salads. If I go out for a meal I would rather have a starter than a dessert. I grew up not having dessert after dinner and I haven't become a dessert fiend. Nor do I binge on sweet things even though I didn't have them as a child. I find it sad that having these things every day is what is considered 'normal' rather than appreciating good food as a whole.
singers, the point you made about age is important and I wanted to touch on silly's point about restricting foods. At what age does that actually kick in? Do you really think that not giving a 2 year old chocolate is going to have an impact on him for life? Will he start bingeing on it as a teenager because he was denied it for those first few years? I am firmly of the belief that while they don't know anything about it there is no point in giving it to them. DS1 is obviously old enough to know what it is and he does have it occasionally. It is not banned, just not given regularly and he doesn't expect it or demand it when we go to a shop. I realise that this will change as he gets older but I am going to take advantage of it right now because I know he doesn't need it.
Honestly, the only thing we differ on is the frequency we give sweet things and (probably) the age at which we start giving them. I haven't banned anything but I am under no illusion that they are good/necessary etc. I am bringing my children up the way I was brought up - limited sweet things and no dessert after every dinner because I know it worked out fine for me. Most of you are probably bringing up your children the way you were brought up because you feel it worked out fine for you. I don't think there's anything wrong with that until you start trying to justify the sweet things for their nutritional value or criticising others/calling them smug/controlling/obsessive or orthorexic 
because they don't feel the same way.