|Image 1: SAD or just mad? It does in fact look like you better stick to Royal TS, French fries & co instead of following a low fat diet according to the guidelines of the National Cholesterol Education Program if you care about your heart health.|
Scientists and their interpretation of a "high fat" diet...
I guess, those of you for whom this is not the first visit to the SuppVersity will be aware that I have made a habit of looking at the data first, to make up my mind, before I even take a closer look at the scientists interpretation of the latter (this is what is usually called the "conclusion"). And, geez! The "high-fat diet", the Valérie Guay and her colleagues advertise in the title of their paper turned out to be another case of the standard American diet, the relative fat content of which (32% of total calories) is not exactly, what's on my mind, when I think of a "high fat" diet.
|Figure 1: Relative macronutrient composition of the baseline and the isocaloric test (high and low fat) diets (left); total fiber, cholesterol and phytosterol content, as well as polyunsaturated to saturated fatty acid (PUFA/SFA) ratio and total fat in % of total calories (right; data calculated based on Guay. 2012)|
SAD! Standard American Diet beats the nasty small LDL particles out of a healthy low fat diet
In fact, a closer look at the somewhat cryptically presented study results revealed that, at least as far as the measured outcome variables of this particular study are concerned, the exact opposite was the case: It was not the purportedly healthy low-fat diet which was designed according to the recommendations of the National Cholesterol Education Program Adult Treatment Panel III (cf. JAMA. 2001) which induced favorable changes in the lipid profile of the twelve initially healthy normal-weight male volunteers (~27.1y; BMI 25.2kg/m²) who took part in this 3-day randomized, double-blind, crossover study, but the calorie-, fiber- and vegetable- and animal-protein-wise identical "high fat" diet, which had been designed in the image of the infamous "standard American diet" (SAD).
|Figure 2: Lipid profile (left) and its relative changes (compared to baseline, right) in response to the 3-day dietary intervention (data calculated based on Guay. 2012)|
|Figure 3: Relative distribution of LDL particle sizes (left), cholesterol content (mmol/L) of LDL fractions (middle), and mean LDL particle size and LDL peak particle diameter (LDL-PPD; right); * indicates p < 0.05; ** indicates p < 0.001 (data adapted from Guay. 2012)|
[...] also associated with a significant increase in LDL particle size (255.0 vs 255.9Å; p = 0.01) and a significant decrease in the proportion of small LDL particle (<255.0 Å) (50.7% vs 44.6%, p = 0.01).And although Guay et al. are quick to point out that "because the present study was only conducted in men, the results cannot be generalized to the whole population", I would say that these results should at least.make you reconsider if following a "healthy low fat diet" in accordance with the dietary guidelines of the National Cholesterol Education Program will help you lower your risk of heart disease... unless, of course, you have already popped so much Lipitor & co that the chronic lack of cholesterol is already hampering your cognitive abilities -.what? Ah, yes... of course, the favorable results occur only if you take you daily dose of statins with your low fat meals... right, how could I forget that ;-)