title: Diets rich in Maillard reaction products affect protein digestibility in adolescent males aged 11-14 y.
abstract: BACKGROUND
  Adolescents are nutritionally at risk because of their physiologic needs and dietary habits. Maillard reaction products (MRPs) are widely consumed by this population, mainly as a result of their high intake of fast food and snacks.
  
  
  OBJECTIVE
  We compared the effects of diets with different MRP contents on dietary protein utilization in adolescent males aged 11-14 y. The brown diet (BD) was rich and the white diet (WD) was poor in MRP content (hydroxymethylfurfural: 3.87 and 0.94 mg/kg; fluorescence intensity: 21.04% and 7.31%, respectively).
  
  
  METHODS
  In a 2-period crossover trial, 18 healthy adolescent males were randomly assigned to 2 groups. The first group consumed the WD for 2 wk, observed a 40-d washout period, and then consumed the BD for 2 wk. The second group received the diets in the opposite order. Subjects collected urine and feces on the last 3 d of each dietary period. Fasting blood samples were collected after both periods.
  
  
  RESULTS
  Compared with consumption of the WD, consumption of the BD resulted in 47% higher fecal nitrogen fecal excretion (P = 0.002), 12% lower apparent nitrogen absorption (P = 0.000), and a 6% lower nitrogen digestibility (P = 0.000). The apparent nitrogen retention and the utilization of ingested nitrogen did not differ significantly between the diets, although values after the BD tended to decrease. Serum biochemical variables related to nitrogen metabolism did not differ significantly.
  
  
  CONCLUSIONS
  The consumption of a diet rich in MRPs negatively affects protein digestibility. The possible effects of an excessive intake of MRPs during adolescence warrant attention, and long-term effects should be considered.
authors: Nutrition Unit, Estación Experimental del Zaidín, High Spanish Council for Scientific Research, Granada, Spain. isequer@eez.csic.es
authors: Isabel
authors: I
authors: Seiquer
authors: José
authors: J
authors: Díaz-Alguacil
authors: Cristina
authors: C
authors: Delgado-Andrade
authors: Magdalena
authors: M
authors: López-Frías
authors: Antonio
authors: A
authors: Muñoz Hoyos
authors: Gabriel
authors: G
authors: Galdó
authors: María Pilar
authors: MP
authors: Navarro