People from Asia tend to live on a vegetable and fruit diet, while eating meats low in fat such as fish. They eat very little bread-wrapped foods such as sandwiches, hamburgers, bagels, paninis, etc. Few of them suffer from obesity, and obesity for them does not increase with age. However, some immigrant families who do move to America and adopt American bread-based foods, like morning bagels and lunchtime sandwiches, do start showing signs of obesity - more weight, higher blood pressure, and higher cholesterol.
Which of the following most logically completes the argument?
Though suggestive, these facts do not establish bagels and sandwiches as the culprit in obesity, however, because _________.