Another interesting study published last week, comparing the impact of the "traditional anti-CVD diet" with the Mediterranean diet.
The study by Institut d'Investigacions Biomèdiques in Spain observed a number of adult individuals with high risk of CVD (cardiovascular disease). The individuals suffered from a range of metabolic disorders, including obesity, high blood pressure, high triglycerides, high plasma glucose etc - all associated with increased risk of death from CVD.
Some were put on the "recommended" diet for people with CVD: essentially low fat, with an overall calorie restriction. The others were put on a Mediterranean diet, which consisted of fruits, vegetables, lean proteins, and fats (olive oil, nuts and seeds), with no calorie restriction (i.e. eating to satiety). The Mediterranean diet consisted of around 50% total fat intake (as percentage of total kcal consumed).
The subjects were observed over a period of 1 year and their metabolic health was assessed throughout and at the conclusion of the study.
The results were not surprising to me but perhaps to many of those educated in 1980s-1990s medicine: the high fat no calorie restriction Mediterranean diet resulted in far better improvements in metabolic health and reduced risks for CVD when compared to the low fat calorie-restricted diet.
The study was not perfect:
- While the Med Diet group didn't gain weight, they didn't lose much (my guess that this was due to lack of physical activity and abundance of grains and legumes in the diet)
- The scientists hypothesized that the subjects on the Med diet were experiencing improved fat oxidation (they became better at burning fat) - however this was not tested for saturated fats, only mono and poly unsaturated fats from olive and oil and nuts/seeds.
In any case, the evidence remains compelling that a higher fat diet resulted in lower CVD risks when compared to a diet designed to lower CVD risks...
I'm copy/pasting below the conclusion from the study, followed by a link to the full literature.
"Since the primary endpoint for the treatment of MetS is to reduce the risk of CVD, traditional dietary recommendations such as those proposed by the NCEP, AHA and NHLBI essentially involve following a low-fat diet and achieving weigh reduction by a combination of reduced caloric intake and increased physical activity. In our study, however, we found that a high-fat (>40% of energy) non-energy-restricted diet showed a reduction in MetS prevalence without the need for weight loss or prescribed physical activity. There are several important aspects to consider regarding the MD followed in this study. First of all, it is highly palatable, decreases hunger, and promotes satiety, hence improving long-term adherence compared to low-fat energy-restricted diets 
. Therefore, the results of this study suggest that there is no rationale for maintaining the fear that a MD rich in fats of vegetable origin may cause weight gain, and that it may be a useful alternative to traditional low-fat diets for the dietary treatment of MetS."