[Effect of 2 different reducing diets on the concentration of HDL cholesterol in obese adolescents]

Serum lipids, lipoproteins, apolipoproteins and fatty acid composition of the major serum lipid classes were determined in fifteen obese adolescents (9 girls and 6 boys, mean age 12.5 +/- 1.2 years, mean overweight 55 +/- 21%) undergoing two weight reduction regimens, differing in fatty acid pattern. The two diets were equal as regards to total energy (approx. 1200 kcal/5100 KJ), protein and carbohydrate content, but differed in the P/S ratio (Diet A: 0.36 +/- 0.19, Diet B, 0.82 +/- 0.44). After eight weeks of treatment with Diet A the patients were switched over to the Diet B. Weight loss during the eight weeks was similar (Diet A: 9.8 +/- 2.1%, Diet B: 7.5 +/- 1.3% reduction of overweight). Diet A resulted in a slight reduction of total and LDL-cholesterol, triglycerides, Apo AI, AII, and B concentrations. HDL-C levels fell significantly from 51 +/- 17 mg/dl to 43 +/- 15 mg/dl (p less than 0.01). Linoleic acid concentrations declined in all major serum lipid classes, in particular in triglycerides and phospholipids (p less than 0.001), whereas arachidonic acid increased in phospholipids (p less than 0.001). After the Diet B a further decline of total cholesterol, LDL-C, triglycerides and Apo B concentrations could be observed, however, HDL-C levels returned to pre-treatment levels (50 +/- 10 mg/dl). Linoleic acid concentrations and arachidonic acid values returned to baseline values. We conclude from this study that in obese adolescents a hypocaloric diet enriched with polyunsaturated fatty acids is associated with a reduction of total-, LDL-C and Apo B concentrations, but with no major changes of HDL-C levels.(ABSTRACT TRUNCATED AT 250 WORDS)