Which statement best evaluates the claim that bread and potatoes are a good source of protein for a typical human diet?

• A. True; bread and potatoes are among the highest-protein foods because they contain complete proteins with all essential amino acids in high amounts.
• B. False; bread and potatoes contain no protein at all and therefore cannot contribute any dietary amino acids.
• C. True; bread and potatoes are classified as protein foods because most of their calories come from protein.
• D. False; bread and potatoes are primarily carbohydrate-rich foods and generally provide less protein per serving than protein-rich foods such as legumes, meat, eggs, or dairy.

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the nutritional composition of bread and potatoes. Both are primarily sources of carbohydrates, with bread made mostly from grains and potatoes being a starchy vegetable.
2. Step 2: Recognize that protein quality depends on the presence of essential amino acids. Complete proteins contain all essential amino acids in adequate amounts, typically found in animal products and some legumes.
3. Step 3: Evaluate the protein content in bread and potatoes. While they do contain some protein, the amount is relatively low compared to protein-rich foods like meat, eggs, dairy, and legumes.
4. Step 4: Consider the concept of protein completeness. Bread and potatoes generally do not provide complete proteins with all essential amino acids in sufficient quantities.
5. Step 5: Conclude that bread and potatoes are not among the highest-protein foods and are not classified as protein foods based on their macronutrient profile; they mainly contribute carbohydrates to the diet.