That claim as restated in the original article:
For many people, low-fat diets are even worse than moderate or high-fat diets because they’re often high in carbohydrates from rapidly digested foods such as white flour, white rice, potatoes, refined snacks and sugary drinks.The article also focuses on saturated fats having more complex effects on the body than most people imagine. Trans-fats, however, are still given a thorough and resounding negative review.
The USDA’s kind words about vegetarianism in its latest guidelines (eg: “On average, vegetarians consume a lower proportion of calories from fat (particularly saturated fatty acids); fewer overall calories; and more fiber, potassium, and vitamin C than do non-vegetarians.”) and the link above prompted Wilde to give some analysis:
First, there is the scientific evidence that lowering saturated fat reduces risk of heart disease [contrary to Wartman’s claim]. … For example, Harvard scientist Walter Willett has long argued that replacing saturated fats with unsaturated fats saves lives, and that refined grains and simple carbohydrates are no healthier than unsaturated fats. The new Dietary Guidelines seem to me in complete agreement. …While some people have complained that the USDA focuses too much on "saturated fat" and not enough on "which foods to avoid," the guidelines do contain this handy chart of where most of us get our saturated fats:
Note that this isn't "which foods have the most saturated fats" but "where do we get our saturated fat"? More of us drink reduced-fat milk than whole milk, so we as a nation get more saturated fat from the reduced fat milk, even though it contains less saturated fat than whole milk.
Wilde's article got a fairly intense comment section, with Wartman defending herself as I quoted at the beginning. He responds to her rebuttal: “The point of difference is whether low-saturated-fat diets are unhealthy. You say yes. I say, "I doubt it." Strong claims require strong evidence.”
She disagrees with his characterization again. Her one point is not whether LSF diets are unhealthy or not, but that high refined carb diets are. “There’s a big difference here -- one could easily eat a diet low in saturated fats that's also low in refined sugars and grains and potentially be very healthy. … No one diet will work for everyone. To simplify my argument into one inaccurate sentence that says I think "low-saturated-fat diets are unhealthy" is not only untrue, but does a disservice to people trying to make sense of the issues.”
I think one could be forgiven for thinking she meant that based on the article she wrote.