A counting system for magnesium-rich foods

This study is to establish an user-friendly counting system for magnesium-rich foods, so as to help people plan a diet with an adequate amount of magnesium. Foods were classified into 12 categories. Three principles were employed to determine the portion sizes: 1) using the standard portion size for foods. For example, one serving of meat is 35 g; 2) using the median intake size for each food category, calculated from the 1993-96 Nutrition and Health Survey in Taiwan (NAH-SIT). For example, per serving for bread or cake is 60 g; and 3) using the weight of one or several piece (s) of food, such as one banana. Given the above-designated portion sizes, the magnesium content for each food was calculated based on "one point is equivalent to 20 mg of magnesium," and then the food was placed into the corresponding point-group. The results showed that whole-grain cereals were a generally good source of magnesium. For example, wheat germ and wheat bran were rated as 6 and 8 points, respectively. In addition, most of the nuts and nut products were 1 to 3 points; the dark green leafy vegetables, three-colored amaranth, spinach, and madeira vine were 3 points or more. For adults over 19 years old, a daily consumption of 10 points of magnesium-rich foods along with other foods provides a diet meeting the Dietary Reference Intakes (DRIs). People may switch from the low-magnesium-point foods to the high-point ones in the same categories to achieve the level recommended by the DRIs.