Interesting. But perhaps people switch from full-fat dairy to the reduced-fat versions after they realize they've made unhealthy eating choices that have already increased their risk of cardiovascular disease? I also notice that "low-fat" foods tend to make up for the low fat in other ways, like by having more sugar and salt. So people think they are "eating healthy", but they actually aren't; they're replacing a bit of fat and its soluable vitamins with high fructose corn syrup. Not good. (And, of course, they don't exercise.)
I also notice that people tend to lump fat from their cheeseburger into the same mental category as fat from things like avocados, peanuts, salmon, and olive oil. But the monounsaturated fat from plants and fish is not particularly harmful for you, except that it's very calorie-dense. Saturated fat is bad for you beyond the number of calories you get from it. Unfortunately, dieters don't realize this, and buy their low-fat-but-high-sugar ice cream while eschewing "high-fat" salmon and peanut butter. Which is bad for you.
(Personally, I drink 1% milk, but otherwise don't bother with "low fat" things. But I do avoid sugar and salt, and that has had a measurable effect on my health. I lose weight faster now that I don't put sugar in my tea, and my blood pressure has gone down since I stopped eating so much salt. Not that either were abnormally high to begin with, though.)
Anyway, the problem with the popular notion of dieting is that you don't get anything out of micro-optimizing away one nutrient.
His bias shows clearly in my view. He complains about large scale epidemiological studies (in the links you provided) and then uses what seems like a relatively small study to back up his claims (in the parent story).
Large scale epidemiological studies may have problems but they are enough to tip the burden of proof towards those who would disagree with them. It is certainly better than relying on some notions of the diet that our primitive ancestors may have had - especially considering that our current circumstances are very different and our life spans are already greater. To me this is a case of naturalistic fallacy.
"Large scale epidemiological studies may have problems but they are enough to tip the burden of proof towards those who would disagree with them."
No! Other things are often highly correlated with diet, and has massive effects on cardiovascular health (exercise in particular). Only randomized controlled dietary trials can be trusted for predictive power.
According to Wikipedia, "the authors noted that randomized controlled clinical trials in which saturated fat was replaced with polyunsaturated fat observed a reduction in heart disease, and that the ratio between polyunsaturated fat and saturated fat may be a key factor."
The actual paper is "under embargo", so I have no idea if it actually says this or not. YMMV.
Without knowing more details it's impossible to know what this means. If this is the same paper the article we are commenting on talked about, then the article appears to have misrepresented the conclusions of the study.
In any case, not all saturated fat is equal. Not all polyunsaturated fat is equal, either. For example, I'd bet it would make a big difference whether the dairy fat was from homogenized milk or some other form (cheese, yogurt) that was not homogenized. It usually doesn't seem to even occur to the authors of studies that such details might make any difference at all.
Saturated fat is not "bad" for you. Not getting enough essential fatty acids (polyunsaturated fats) is bad for you. Not having enough unsaturated fats either through dietary intake or conversion from EFAs is bad for you.
Having a high Omega-6 to Omega-3 EFA balance may be bad for you.
I think the problems with popular notions of dieting - and this is going to get OT, but my mind's on it at the moment - are intermingled with problems of praise and self-esteem in society. You can see, on almost any occasion, a women's magazine at the grocery store which will say "lose 10 pounds!" next to a picture of a giant chocolate cake slice. Anyone who has successfully dieted knows that it involves lifestyle changes, thought and research into making better decisions, and a gradual build of accomplishments and confidence over months/years, not a quick-fix recipe, and if you succeed, the chocolate cake will essentially leave the dinner table and your mind.
But the mindset of a fragile ego is to want an immediate resolution and insignificant changes to habits - whether it's through badgering others for acceptance("there is no problem with me, right?"), falling for snake-oil pitches, using drugs, buying expensive medical procedures, etc. We don't educate people towards building real self-esteem, so we end up with a massive segment of our population perpetually sitting on the verge of severe emotional distress.
This is especially unfortunate because, at least how I understand it and was raised, self-esteem is cheap to create. It's formed by focusing the dialogue on real accomplishments and immediate consequences and avoiding attribute-based judgments(which have an unbounded magnitude and finality that make them impossible to frame in a positive way). You can find this theme running through books ranging from the classic "Between Parent and Child" (which my parents used), to a variety of books on business and networking, to Cesar Millan's dog training method.
Going back to dieting, the consequence of our corrupted dialogue is a glut of poor advice, guilt trips, and fad-following. Now that I've tried actually "playing" with diet, I've discovered that it can be a lot of fun; you just have to get away from good food/bad food/ideal numbers dogmatism and take a more from-the-ground-up, intuitive approach.
Avoiding salt also has the side effect of avoiding a lot of processed foods, which are unhealthy in other ways. Here's a NY times article about how salt has always been a big part of processed foods:
Obviously avoiding sugar is going to mean you consume less calories and thus likely to lose weight. Sugar is not on its own unhealthy though.
Avoiding salt means you're avoiding tons of processed foods and drinks. I would bet that it's the avoidance of those foods that are making you healthier and not necessarily the salt.
Seeing "1%" or "2%" on the lower-fat milks suggests a lot of fat has been taken out -- you might even naively think 98%+ of the original fat content. But in fact 'whole' milk is only 3.25-3.5% fat -- not much difference.
And, the process for creating 1% or 2% varieties involves stripping all the fat out -- taking out other things as well -- then building the milk back up to the desired fat/vitamin/milk-solid levels with additives.
This is not in conflict with your point above that nutrients are removed along with the fat in processed milk, that are then readded (e.g. vitamins A and D), but it's important to realize that those single digit percentages refer to fat in terms of weight.
Ignoring the water content of milk, and looking solely at the caloric percentages, the fat ratio is:
Whole Milk: 48% fat
2% Milk: 33% fat
Skim milk: 5% fat
Referring to fat content of foods and beverages by percent of weight is generally not a useful measure for nutritional purposes. By that thinking, if one were to drink a few glasses of water and then eat 1/2 a pound of ice cream, they could claim they had a low fat meal, because the total grams of fat from the ice cream is small compared to the total water weight of the two items they consumed.
'Whole' milk isn't only 3.25-3.5% fat, that's the processed one sold in stores. Milk directly from a cow can contain > 5% of fat (see http://en.wikipedia.org/wiki/Milk), and the taste is quite different from the processed one.
I also notice that people tend to lump fat from their cheeseburger into the same mental category as fat from things like avocados, peanuts, salmon, and olive oil. But the monounsaturated fat from plants and fish is not particularly harmful for you, except that it's very calorie-dense. Saturated fat is bad for you beyond the number of calories you get from it. Unfortunately, dieters don't realize this, and buy their low-fat-but-high-sugar ice cream while eschewing "high-fat" salmon and peanut butter. Which is bad for you.
(Personally, I drink 1% milk, but otherwise don't bother with "low fat" things. But I do avoid sugar and salt, and that has had a measurable effect on my health. I lose weight faster now that I don't put sugar in my tea, and my blood pressure has gone down since I stopped eating so much salt. Not that either were abnormally high to begin with, though.)
Anyway, the problem with the popular notion of dieting is that you don't get anything out of micro-optimizing away one nutrient.