PLASMA AMINO-ACIDS CHANGES IN OBESE PATIENTS ON VERY-LOW-CALORIE DIETS

The reduced feeling of hunger alleged by obese patients on very low-ca lorie diets (VLCD) could be supposed due to restoration to a normal le vel of plasma TRP:LNAA ratio previously found lowered in these subject s. We tested this hypothesis measuring weekly the changes of plasma am ino acid concentration in obese individuals who followed a 5 week slim ming regimen consisting in a powdered formula diet (500 kcal/d). A dec rease in plasma TRP:LNAA ratio was seen, since tryptophan decreased, w hereas valine and isoleucine increased over time. An increase in plasm a lysine, threonine, glycine and aminobutyrate was also observed The e arly decrease shown by alanine and glutamate was followed by an increa se in the last weeks of the study. Our hypothesis was not confirmed, s ince VLCD failed to carry back the plasma TRP:LNAA ratio to a normal l evel.