I just finished reading, to my dismay, an article by the resident dietitian for msnbc.com news, health section, who states in an article, I believe posted today, that saturated fat is even more dangerous than previously thought.

She mentions a new study that shows that saturated fat plays havoc with insulin levels. It dismays me that she provided no link or reference to that study, so that I could read it myself. For instance, I wonder if in that particular study, the folks who ate a lot of saturated fat also ate a lot of carbohydrates along with it.

Dr. Mike, can you please comment? Thanks!

Hi Sheryl–

I did indeed read the insipid comments of this woman. There is no arguing with such unshakable stupidity. Whenever anyone resorts to the old “many studies have shown” or “recent studies have shown” argument without listing said studies, you know that person doesn’t have a clue as to what any studies–recent or otherwise–actually show.

MRE

The idea of studying diets with an exclusive focus on calories seems likes an exercise in ‘tunnel vision’, i.e. treating the body like it’s an engine, rather than as an extremely complex biochemical feedback loop. Intuitively, a nutrient deficiency would seem likely to be interpreted by the body as an indication of starvation and thus tend to promote fat retention. On the other hand, any deficiency that interferes with absorption of nutrients and other anabolic metabolism (processes that build and repair the body) would likely promote weight loss.

Reviewing the NIH website on Vitamins and Supplements (http://ods.od.nih.gov/Health_Information/Vitamin_and_Mineral_Supplement_Fact_Sheets.aspx) shows only Calcium deficiency may be associated with weight gain while Chromium deficiency may be associated with diabetes and initial weight loss as symptom of diabetes. Notwithstanding the above examples, no vitamin or mineral deficiency appears to be associated with weight loss as a primary symptom of the deficiency. Your diet book (I know you hate that term) and many others recommend various supplements, so that it is clear that you don’t share the calories only perspective. Incidentally, like the others I have to congratulate you on the penetrating insights into this and other scientific articles. Thanks for the time and space.

Hi Mark–

I agree that micronutrients are important and are a necessary component of any diet. But, they don’t provide calories. In evaluating a diet strictly in terms of the energy it provide, one can only look at the macronutrients and/or the total caloric intake.

MRE

Wouldn’t micronutrients be a fifth?

No, micronutrients wouldn’t count as a fifth in these calculations because micronutrients contain no calores. Weight-loss studies usually only look at the caloric content or of the macronutrients that make up that caloric content.

MRE

The large and small are measured by electrophoresis whereas VLDL is measured by ultracentrifugation. And, small and large aren’t really small and large–LDL particals are on a continuum from large to small. What you want to have is more of the larger and less of the smaller.

MRE

Regarding the relationship between glycemic load and CRP, though, the one detail that sort of smears the studies a little (granted, mainly Willet’s work) is the use of the food-frequency questionnaire. Do you know of other studies where the estimation of the glycemic load has been done based on a 24-hour food journal for example?

One study comes to mind, where the study subjects were given the food ahead of time, every week for the duration of the study. They would eat one meal on Monday and then go home with the rest of the food for the week (Pereira et al. JAMA. 2004;292:2482-2490). Interestingly, in the low-glycemic load food, fructose was included. So, the inclusion of seemingly ‘low-glycemic’ foods but that affect the metabolism just as bad as other carbohydrates is another detail that makes me not put too much stock in the glycemic load and/or glycemic index, even though the trend is clear. Ah… maybe I’m being too picky!

I just wanted to comment about other studies where low carbohydrate diets have been really used as such, for example those from Jeff Volek in which he uses what he calls “Very Low Carbohydrate Diets”, or VLCD, which I just call ‘true low-carb diets’. His studies have clearly shown that VLCDs improve the lipoprotein profile independently of weight loss. Of course, some people still point out that even if carbohydrate restriction improves lipid profiles, is still not as effective at lowering LDL cholesterol (LDLC). Go figure… how can a lipid profile improve but one of the main players doesn’t… Amazingly, the naysayers do recognize that carbohydrate restriction consistently improves postabsorptive and postprandial triacylglycerols (TAGs), HDL cholesterol (HDL-C), and the distribution of LDL-C subfractions to a greater extent than low-fat diets. So… the lipid profile does improve, doesn’t it? You gotta love semantics sometimes!

I haven’t read the article you discuss yet but I’m curious to know if the authors cited any of Volek’s work. It seems to me that their question has already been addressed.

What does seem to be independent of the diet, however, is the improvement in some inflammatory markers as Volek and others have shown comparing VLCDs and low-fat diets. Apparently, the improvement in inflammatory markers is similar and related more to weight loss than the type of diet. Even if that is so, given the boat load of other benefits brought about by carbohydrate restriction, that is even a better way to improve both, lipid profile and inflammatory markers.

Hi Gabe–

Thanks for the commentary. Volek’s work does seem to show that improvement in inflammatory parameters is more a function of weight loss than diet composition, but the works of others has shown a relationship between the glycemic load, i.e., carb content, and an increase in C-reactive protein.

MRE

The other point is the final sentence of the Results

“lipoprotein changes with the higher saturated fat intakes were not significantly different from those with the lower saturated fat intakes, except for LDL cholesterol, which decreased less with the higher saturated fat intake because of an increase in mass of large LDL.”

Finally, a plausible explanation for one of the few confirmed items of the lipid theory, that consumption of saturated fat raises cholesterol levels and especially the LDL cholesterol. It does this by increasing their size and thus their mass. Continuing this train of thought, consumption of saturated would actually appear to be anti-atherogenic (i.e. protective against heart disease) by raising HDL (the other ‘good’ cholesterol) and making the LDL less dangerous.

All of this may seem obvious, but until bariatrics (the branch of medicine that deals with the treatment of obesity) has a scientific basis, the obesity problem will worsen. Thanks for the time and space to comment.

Hi Mark–

Well argued. I’ve said the same thing about saturated fat for years. It raises HDL, increases LDL particle size, and is one of the only agents known that reducles Lp(a).

Old habits die hard.

MRE

BTW, the June issue of Allure magazine (just out) page 139 has our book mentioned with before after pix of a gal we trained to lose fat off her legs in 8 weeks. We did good. But the brainiac editor botched the details however stating the our gal lost a total of 5 pounds in 8 weeks using Slow Burn and following the Slow Burn Power Eating Plan in the book.

Not so. And I gave them the details in full!! It’s as if they could not believe it so the refused to print it.

She lost 5 pounds alright – 5.45 to be exact, but gained 4.8 pounds of lean making a total fat loss of 9.8 pounds! But here’s the kicker – she started out lean already and moved in to the ideal range on my body fat analyzer gizmo. THAT is no easy feat! Low carb and Slow Burn rules big time! Everyone else exercised for 5 + hours a week. Our gal – 1 hour or less.

Hi Fred–

Thanks for the kind words. As to the change in lean mass, the authors of the study did note that

“There was also a trend for a greater reduction in percentage body fat with the lower-carbohydrate diets.”

MRE