- Compare expensive and inexpensive nutrients such as vitamins and Ca2+ supplements. Compare contents and quantity. What makes the difference in the price? Use the Merck Index or a Physician's Desk Reference to identify ingredients.
- How does a microwave work? Why must you vent the food in a microwave oven? Microwaves are a form of electromagnetic energy, with a shorter wave length and higher frequency (more energy) than radio waves and longer wavelength and shorter frequency than visible light. Microwaves are like radar emissions and are absorbed by water, but are reflected by metal; they pass through glass, paper, and plastic. When the energy is absorbed, primarily by the water in the food, the molecules betin to move rapidly and produce heat to cook the food. They do not cook "from the inside out," but if allowed to stand, the heat will be conducted inward, cooking as it travels. Because the steam produced from the liquid water in the food can become very hot when microwaved in a closed space, all food should be vented and care used before opening microwaved packages.
- Read and interpret food labels. The ingredient present in the greatest concentration is first on the list. Answer the following questions:
- How may cups of cereal will this package provide? [2/3 x 15 = 10 cups]
- How many calories are in one serving of the cereal? [85 cal]
- How many calories are added when you eat the cereal with 1/2 cup of whole milk?[75 cal]
- Does a serving of cereal plus milk provide more grams of protein, fat, or carbohydrate?[Carbohydrate]
- If you are 18 years old, you need 80% of the U.S. RDA for Vitamin C. How many servings of this cereal would you have to eat in order to meet your need for Vitamin C? [One serving provides 20%; to get 80%, one needs four servings.]
- If you ate two cups of this cereal, what percent of the U.S. RDA for niacin would be supplied by the cereal alone? [2/3 cup provides 20%, and to get 2 cups, you need to eat three servings; hence, 3 x 20% = 60%]
- How much more niacin would be supplied by 2 cups of this cereal plus milk? [2/3 cup with milk provides 25%, and 2 cups would supply 75%; hence, 15% more.]
- What ingredients are found in the smallest and largest amount? [Vitamin B12 and wheat bran, respectively.]
- What minerals are provided by this cereal? [Sodium, potassium, calcium, iron, phosphorus, magnesium, and copper.]
- Which would provide less fat when used with this cereal: Vitamin D fortified or skim milk? [Skim milk contains less fat than whole milk.]
- What is the function of the BHA? [Food preservative]
- How is Vitamin C identified in the list of ingredients? [Sodium ascorbate]