RESUMEN
Compliance with diets containing different amounts of protein was studied in 15 nonobese type 2 diabetes patients (13 males aged 38-69 y). A method based on interviews and training in the technique of weighed diet records was used. Protein intake recorded by the patients was evaluated on the basis of 24-h nitrogen output (criterion standard measurement). Three diets were prescribed in random order, each lasting 4 wk: usual diet (UD), chicken diet (CD) (both with 1.2-1.5 g protein/kg body wt), and low-protein diet (LPD; with 0.5-0.8 g protein/kg body wt). Diets were isoenergetic and similar in fat content. Nutritional status was not altered during the study according to anthropometric indexes (body mass index, triceps skinfold thickness, midupper arm muscle area, and waist-to-hip ratio) and laboratory data (serum albumin, hematocrit, and lymphocyte values). The correlation of protein intake recorded on the weighed diet records with that estimated by nitrogen output was 0.64 for the UD (P = 0.01), 0.79 for the CD (P < 0.001), and 0.66 for the LPD (P = 0.008). No difference was found in mean protein intake (g/kg body wt) calculated from the weighed diet records and nitrogen output for the UD (1.37 compared with 1.36 g/kg body wt) and CD (1.38 compared with 1.32 g/kg body wt). With the LPD, patients did not consume more protein than prescribed, but underreported their actual protein intake by 13% (0.68 compared with 0.78 g/kg body wt, P < 0.05) . In conclusion, the method of weighed diet records was sufficiently accurate for assessing protein intake in this sample of type 2 diabetes patients.