The ratio of high-density lipoprotein cholesterol to triglycerides has been documented as one of the most important cardiovascular risk factors.1 However, Michelle Fung and Jiri Frohlich2 perpetuate the myth that a low-fat diet will be helpful in the management of this problem.

Lichtenstein and Van Horn3 extensively reviewed this approach a few years ago. Examination of their evidence suggests that a low-fat dietary regimen will produce a result opposite to the desired effect: triglyceride levels will actually increase.

This outcome is not surprising if one considers that insulin resistance may be one of the driving forces behind elevated triglyceride levels. In fact, insulin resistance may be the culprit in many of the problems observed in high-triglyceride states.4,5

Since only 3 macronutrient components are available for any diet, a low-fat diet automatically entails increases in the protein and carbohydrate fractions. Most people eat a fixed amount of protein, so the majority of the calories would be shifted to carbohydrates. The problem occurs when the person consumes grains with a high glycemic index, rather than vegetables, as an alternative to fat. The grains are rapidly metabolized to simple sugars, which are clearly associated with elevated triglyceride levels.6

An alternative therapeutic approach is to radically reduce consumption of all grains and simple sugars. In contrast to the pharmacologic options that are traditionally applied, it is simple and inexpensive to substitute green leafy vegetables, which have a low glycemic index, for grains and sugars, and there are no toxic effects.
From：http://articles.mercola.com/sites/articles/archive/2003/04/16/triglycerides-part-two.aspx