There is a well-established link between fat intake and heart disease. [1] Both saturated fat and trans-fat contribute towards increased blood cholesterol and clogged arteries. That research didn't become invalid just because you can lose weight on a low-carb diet.
Now unsaturated fats at moderate levels? Absolutely necessary. A bit of saturated fat in your diet? No problem. But a diet that consists of upwards of 20% saturated fat? You might as well go on low dose aspirin while awaiting your heart attack.
(Note: there are conflicting studies, but meta-analysis seems still to side with this contention. Really the only desenting papers are funded by bigAg, on very high fiber diets or had testing flaws - http://en.wikipedia.org/wiki/Saturated_fat_and_cardiovascula...)
Actually, there's a lot of counterevidence to this "well-established" link between fat and heart disease. The classic on the subject is Gary Taube's "Good Calories, Bad Calories." But also, check out William Davis' blog (he's a cardiologist who recommends a low carb diet.) Or this:
Remember when eggs used to be bad for you, because they had high cholesterol, and then they became ok again? (http://well.blogs.nytimes.com/2013/01/28/eggs-regain-reputat...) I'm afraid I don't fully trust any source of nutritional information until I've tested it empirically.
Which I did. I cut out all grains and found that my cholesterol plummeted and I lost a lot of weight (and I have more energy.) That's on a moderate fat diet. I'm just one anecdote, of course. I invite people to experiment for themselves.
msluyter correctly points to the Inuits as a good case against what you've said. Their diet consists pretty much entirely fat and meat yet they have lower heart disease and rates of cancer.
Oh not those studies again. Those studies are wonderful until you get to the fact that the Inuit have the shortest life expectancy of any other Canadian group - upwards of 15 years shorter.
So of course you find less heart disease in that group. They're dying of TB, diabetes (of all things) and suicide long before they get heart disease.
"Analysis of the 2001 Census data revealed lower levels of education and income and poorer housing conditions for the Inuit-inhabited areas compared with Canada as a whole. Any or all of these, in addition to lifestyle risk factors and environmental conditions, could be at least partly responsible for the lower life expectancy in those areas.
In the three five-year periods studied, from 1989 through 2003, the infant mortality rate was approximately four times higher in the Inuit-inhabited areas, compared with all of Canada."
