Mel Siff died in 2003. "Established wisdom" at that time did not recommend a low-fat diet at all. He apparently wrote in one of his books that "nutritional scientists" recommend a diet of 10% fat, but that was never the recommendation of major health organizations or "conventional wisdom". The IOM recommended in 2002 20-35% of calories from fat, for example. In 1990 the recommendation was 30% or less.
It seems that Mel Siff didn't follow a low fat vegetarian diet himself, based on his response to a critical article about him: (full response here: http://www.somasimple.com/forums/showthread.php?t=6558 )
Interestingly, I cannot recall anyone by the name of Glassman ever staying in the Siff household or studying me in the laboratory to examine my eating habits, so I am intrigued to know where he found this inside information. The abbreviated tale of my cardiac rehab programme
(http://www.worldfitness.org/drmelsiff.html) certainly said nothing about my specific breakdown of macronutrients in my diet.
Had he read a little more carefully what I wrote, he would have noticed that my diet comprises something like 50-60% lipids (no fried foods, no transfats, no animal fat, plenty of fish) and under 30% carbohydrates (no refined carbs) and hasn't deviated much from that sort of balance for many years - I have never been a lover of high carb diets and have eaten little or no sugar
(other than about 1-2 tablespoons of honey or a few servings of fruit a day). Where on earth does he obtain that nonsense from about my diet?
So, he says there he ate about 50-60% fat. It's strange though that he says "no animal fat" but plenty of fish, which is of course animal fat.