The question is asking which fruit serving size is not appropriate for someone following the American Diabetes Association (ADA) diet. The correct answer is "1 cup of apple juice." The ADA diet is tailored to help individuals manage their blood sugar levels, and thus, portion control is a critical aspect of this diet. It's important to understand that different forms of fruits have different impacts on blood sugar levels. Whole fruits contain fiber, which helps slow down the digestion process and the release of sugar into the bloodstream, making them a healthier choice in appropriate portions.
In contrast, fruit juices, such as apple juice, lack fiber and are more concentrated sources of sugar and calories. Consequently, they can lead to quicker and higher spikes in blood sugar levels. According to ADA guidelines, if fruit juice is consumed, it should be limited to a smaller serving size because of its higher sugar content and lack of fiber. Specifically, the ADA recommends that servings of juice should not exceed 1/2 cup. This is because a full cup of fruit juice can contain the sugar equivalent of several pieces of whole fruit, without the beneficial fiber.
The other options provided - "2 plums," "½ cup unsweetened canned fruit," and "2 tablespoons of raisins" - are generally considered appropriate serving sizes for someone on the ADA diet. These options contain fiber (to varying extents), are more filling, and have a slower impact on blood sugar levels compared to a full cup of fruit juice.
Thus, "1 cup apple juice" is the correct answer as it is not an appropriate serving size for someone managing their diet according to ADA guidelines. To adhere to the ADA diet, it's recommended to consume whole fruits in appropriate portions and limit the intake of fruit juices, especially in larger quantities like a full cup.