Effect of High-Carbohydrate Feeding on Triglyceride and Saturated Fatty Acid Synthesis

Interesting paper at
http://www.ebmonline.org/cgi/content/full/225/3/178

Effect of High-Carbohydrate Feeding on Triglyceride and Saturated
Fatty Acid Synthesis
Lisa C. Hudgins1,

The Rogosin Institute, Rockefeller University, New York, New York
10021

Abstract

It has been known for decades that low-fat, high-carbohydrate diets
can increase plasma triglyceride levels, but the mechanism for this
effect has been uncertain. Recently, new isotopic and nonisotopic
methods have been used to determine in vivo whether low-fat,
high-carbohydrate diets increase triglyceride levels by stimulating
fatty acid synthesis. The results of a series of studies in lean and
obese weight-stable volunteers showed that very-low-fat (10%),
high-carbohydrate diets enriched in simple sugars increased the
fraction of newly synthesized fatty acids, along with a proportionate
increase in the concentration of plasma triglyceride. Furthermore, the
concentration of the saturated fatty acid, palmitate, increased and
the concentration of the essential polyunsaturated fatty acid,
linoleate, decreased in triglyceride and VLDL triglyceride. The
magnitude of the increase in triglyceride varied considerably among
subjects, was unrelated to sex, body mass index, or insulin levels,
and was higher when fatty acid synthesis was constantly elevated
rather than having a diurnal variation. It was notable that minimal
stimulation of fatty acid synthesis occurred with higher fat diets
(30%) or with 10% fat diets enriched in complex carbohydrate. Public
health recommendations to reduce dietary fat must take into account
the distinct effects of different types of carbohydrate that may
increase plasma triglycerides and fatty acid synthesis in a highly
variable manner. The mediators and health consequences of this dietary
effect deserve further study.

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I love this part "Furthermore, the concentration of the saturated
fatty acid, palmitate, increased and the concentration of the
essential polyunsaturated fatty acid, linoleate, decreased in
triglyceride and VLDL triglyceride." Bwahaha. Lo fatters avoid all
those fats only to have their body make it in its most saturated form
and at the expense of good fats.

Another good one "It was notable that minimal stimulation of fatty
acid synthesis occurred with higher fat diets (30%) or with 10% fat
diets enriched in complex carbohydrate."

On Mon, 16 Feb 2004 00:58:33 GMT, Charles Henkel wrote:

OK, one more

http://www.ebmonline.org/cgi/content/full/225/3/175

Introduction: Low-Saturated Fat, High-Carbohydrate Diets: Effects on
Triglyceride and LDL Synthesis, the LDL Receptor, and Cardiovascular
Disease Risk

Robert H. Knopp,

Northwest Lipid Research Clinic, University of Washington, Seattle,
Washington 98104

No abstract, but here are some great quotes

"This symposium was borne out of the observation that low-fat,
high-carbohydrate feeding is associated with an acute increase in
plasma triglyceride concentrations."

"Because the plasma triglyceride and HDL perturbations of low-fat,
high-carbohydrate feeding so resemble the abnormalities associated
with Syndrome X or the familial CHL phenotype, we asked in this
symposium whether the lipid abnormalities of low-fat,
high-carbohydrate feeding might have a similarly negative effect on
cardiovascular health."

"Should the synthesis of palmitic acid be enhanced during carbohydrate
induction, this compensatory effect would have the unwanted effect of
cancelling out or subverting the dietary reduction in intake of
saturated fat, which is the central goal of the low-fat diet teaching
approach."

"The Willet paper (16) finally brings the metabolic observations to a
level of association with cardiovascular disease employing
observational epidemiology. His research indicates that fat
restriction per se is not associated with a reduction in coronary
artery disease (17). More specifically, the substitution of saturated
fat with carbohydrate is associated with no reduction in coronary
artery disease whereas substitution of saturated fat with mono- or
polyunsaturated acids is associated with a reduction in coronary
artery disease in prospective cohort studies (18). As if saturated fat
were not bad enough, Dr. Willet's studies point to the fact that trans
fatty acids cause even greater increases in LDL cholesterol
concentrations than saturated fat and reduce HDL cholesterol and
increase Lp(a) concentrations. "