Veränderungen kardiovaskulärer Risikofaktoren - mit besonderer Betrachtung von Homocystein und hsCRP - unter drei aktuell diskutierten Ernährungsstrategien zur Gewichtsreduktion: Low carb, Low fat und Low fat with reduced glycemic load

Abstract

In the past years, different dietary strategies have been investigated with regards to their effects on weight loss and cardiovascular risk factors. Now such investigation taking into consideration German nutritional conditions till now We performed a randomized trial with 160 overweight to moderate obese women: For 6 month 53 women followed a low-carb diet (LC), 54 women followed a low-fat diet (LF), and 53 women followed a low-fat diet with reduced glycemic load (LFRGL). During the 6 months we measured weight, glucose, lipids, homocysteine and hsCRP. The intake of several nutritional components was analized by a computer assisted program for food recordings. Weight loss was -8,1 + 4,0 kg (LC), -6,3 + 3,9 kg (LF) and -6,8 + 3,5 kg (LFRGL) without significant differences between the three groups (p=0,4868). We observed a higher percentage of drop-outs in the low-carb group (45,3%), compared with 35,2% (LF) and 30,3% (LFRGL). After 4 weeks, only women following the low-carb diet had an increase in homocysteine. In this group, there was no significant decrease in hsCRP at the end of the study either, although the greatest amount of weight loss was observed. A significant reduction of triglycerides could only be seen in the low-carb group as well. The intake of roughage (p<0,0001), folic acid (p=0,0038) and vitamin B6 (p=0,0029) decreased substantially under carbohydrate restriction. To a lesser extent, a decrease in the intake of roughage (p=0,0459) and vitamin B6 (0,0230) was noticed in the group with reduced glycemic load (LFRGL), too. The three dietary strategies are equally effective as far as for weight loss is concerned. However, the significant decrease in the intake of folic acid, vitamin B6 and roughage represents a health concern for a strict low-carbohydrate diet under German nutritional conditions. In combination with an already low intake of folic acid in the entire study population at the beginning of the trial, a low-carb diet leads to a clinically relevant lack of supply of folic acid, resulting in an increase in homocysteine and a missing decline in hsCRP.