The anecdotal evidence was created while testing the theories outlined in the book "Good Calories Bad Calories" by Gary Taubes.
"Since the early 1970s, for instance, Americans' average fat intake has dropped from over 40% of total calories to 34%; average serum cholesterol levels have dropped as well. But no compelling evidence suggests that these decreases have improved health. Although heart disease death rates have dropped--and public health officials insist low-fat diets are partly responsible--the incidence of heart disease does not seem to be declining, as would be expected if lower fat diets made a difference. This was the conclusion, for instance, of a 10-year study of heart disease mortality published in The New England Journal of Medicine in 1998, which suggested that death rates are declining largely because doctors are treating the disease more successfully. AHA statistics agree: Between 1979 and 1996, the number of medical procedures for heart disease increased from 1.2 million to 5.4 million a year. "I don't consider that this disease category has disappeared or anything close to it," says one AHA statistician.
Meanwhile, obesity in America, which remained constant from the early 1960s through 1980, has surged upward since then--from 14% of the population to over 22%. Diabetes has increased apace. Both obesity and diabetes increase heart disease risk, which could explain why heart disease incidence is not decreasing. That this obesity epidemic occurred just as the government began bombarding Americans with the low-fat message suggests the possibility, however distant, that low-fat diets might have unintended consequences--among them, weight gain. "Most of us would have predicted that if we can get the population to change its fat intake, with its dense calories, we would see a reduction in weight," admits Harlan. "Instead, we see the exact opposite." "
http://www.second-opinions.co.uk/taubes.html
http://www.npr.org/templates/story/story.php?storyId=15886898
The Taubes book covers the history of government dietary recommendations and where they come from. it is a real eye opener and explains the years I spent cutting calories with absolutely no weight loss and the 2 years I spent exercising 1 hour a day for 6 days a week over a 2 year period with no calorie increase and didn't lose a single pound.