Magnesium in body building\'s diet

Author(s)

Aline Guimarães Amorim

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2002-09-11

Examining board members

Celia Colli; Tullia Maria Clara Caterina Filisetti; Regina Mara Fisberg

• Advisor: Celia Colli

Abstract

The study evaluated the magnesium comsuption in body building\'s diet (n = 15) according to the new Dietary Reference Intakes (IDRs). Magnesium\'s food sources also were identified of the studied group and in marathon runners\' diet of the same age, so they could be reproduced and analyzed in its total magnesium content. This way, the obtained results in laboratory could becompared with the ones found in food composition tables, also conducting the validity of total magnesium\'s determination methodology . The magnesium dietary consumption (average±standard deviation) was 323±115 mgMg/d and 115±26 mgMg/1000kcal in the the 19-30 year-old group and 345±110 mgMg/d and 110±18 mgMg/1000kcal in the 31 to 50 year-old group, without significant differences among the studied groups. In this scenario, 5 body building athletes had the minimum probability of 70% of adequate magnesium\'s usual ingestion, while 6 showed at least 70% of minimum probability of inadequate magnesium\'s usual ingestion. Should be done a better dietary contribution of the mineral in question, emphasizing a larger food consumption with higher magnesium content. The main boby builders\' Mg food sources were banana, steak, cooked potato, cooked spinach, bean, semi-skimmed milk and oat flakes. Also, for the marathon runners these were represented by banana, com flour, oat bran, bean, steak, cooked fish, okra, chocolate powder, whole-meal bread and cassava. The calibration curve found for magnesium was linear (r = 0,9999), presenting DL and QL O, 15±0, 17 and 0,48±0,55 mgMg/mL In total magnesium determination the certified reference material (NIST) and secundary reference material (AIN93G) presented a variation coefficient (c.v.) of 4,4 and 3,2%, respectively. Even so, the obtained concentration in the NIST reference material was significantly smaller (p <0,05) than the expected value. The analyzed foods had c.v. below the established limit (10%). In the AIN93G reference material and in the oat bran no matrix\'s interference were observed . The total magnesium content found in the analyzed brands of mineral water ranged from 0,5 to 1,2 mgMg/100g. In spite the values above the expected ones, the water doesn\'t contribute with the dietary consumption of magnesium above 7% of EAR, considering the ingestion of 2 liter/d of water. Among the foods submitted to cooking process, okra, spinach, cassava and bean had significant differences (p <0,05) among raw and processed forms. The corn flour, oat bran, whole-meal bread and chocolate powder\'s brands analyzed are different from the expected values, probably due to the different origin of the foods found in the used composition tables. (AU)