Find the Missing Ingredient
Food advertisements and labels bombard us with enticing slogans and attractive images, luring us into consuming the food. But have you ever wondered how nutritious the food is? Have you ever looked at a nutrition facts label and wondered what the columns of words and numbers meant? This activity will shed some light on the label. You will explore serving sizes and nutrients, and might find a discrepancy. Why would the sum of the nutrients not always add up to the total? Like a detective, you will gather the facts, brainstorm ideas and find evidence to support your proposed explanation. Can you crack the case?
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
Food laws and regulations have been around for centuries. Their initial goal was to deter mis-branding food, like mixture cheap corn syrup with nice honey, and selling it as pure honey. The mandatory US nutrition facts label as we know it today is a result of the 1990 Nutrition Labeling and Education Act (NLEA). It informs consumers about what is in their food by listing serving size (the amount of food usually consumed at one time) and basic per-serving nutritional information, including Calorie (energy) content, essential vitamins and minerals, recommended daily amounts of these nutrients. All of this information can be used to make informed decisions when deciding what to eat.
Foods mainly consist of fat, carbohydrates, and protein. These are called macronutrients and provide us with energy.
The other nutrients listed, like Vitamin A, iron, calcium, etc. are called micronutrients. While they are present in much smaller amounts, they still play an important role in a healthy diet. For easy reference, the labels show the percent daily value for most nutrients. This refers to the portion of the daily recommendations for this nutrient one serving provides.
Extra: Groups foods that provide a lot of fats, foods that provide a lot of carbohydrates, and foods that provide a lot of protein. Do some foods belong in two or even all three groups? Do some foods belong in none of these groups?
Extra: Rank your foods from smallest to largest serving size. Are you surprised about the variety in serving sizes?
Extra: Pick a food item you eat frequently and weigh out one serving as listed on the label. Is what you usually eat more, less or about the same as the serving size? Repeat for other food items. Do you observe a pattern in the mismatches in serving size and what you usually eat?
Extra: Nutrition facts labels list nutritional content per serving. Can you calculate nutritional content per 100 grams instead? For example, divide the amount of fats per serving (in g) by the serving size (in g). This will give you the amount of fats per gram of the food. Multiply this by 100 to get the amount per 100 g of food. Now rank your foods from highest to lowest fats per 100 grams. How does this ranking compare to ranking by fats per serving? Which ranking would be more useful for consumers who are looking for food high (or low) in fats? Repeat for carbohydrates and protein.
Observations and Results
Did you notice that for some food items, the sum of the masses of macronutrients (fats, carbohydrates and protein) in a serving is very close to the mass of one serving, while for others it is not? This occurs because water has mass, but contains no macronutrients!
Although consuming enough water is essential for good health, it is not listed on the nutrition facts label. Thus, the water content of food influences the mass, but not the nutritional content, of food. Foods containing water will have servings that weigh more than the sum of the masses per serving of the three macronutrients. The mass discrepancies you observed informed you about the water content of the food items. The more water they contained, the bigger the discrepancy.
Listing nutritional content per serving allows consumers to compare different types of food at a glance, and identify which provides more of a nutrient per serving. Pay attention to serving sizes though! You might find that you usually consume way more or way less than the listed serving size, making these comparisons a little trickier.
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