Final answer:
The limitations of digital imaging methods include the requirement of specialized equipment and the possibility of underestimating usual intake, so the correct option are C, D, and E.
Step-by-step explanation:
The limitations of digital imaging methods are typically related to dietary assessment, not preparing food or collecting samples.
Let me provide you with corrected limitations related to digital imaging methods used in dietary assessment:
A) Expense and effort of preparing more food - This option seems unrelated to digital imaging methods. The cost and effort associated with preparing food may be a concern for dietary studies, but it's not a direct limitation of digital imaging methods.
B) Effort and time to collect duplicate samples - This option also appears unrelated to digital imaging methods. Collecting duplicate samples might be a concern in some studies, but it's not a limitation specific to digital imaging methods.
C) May underestimate usual intake - This is a valid limitation of digital imaging methods. People may alter their dietary habits when they know they are being observed, leading to an underestimation of their usual food intake.
D) Requires specialized equipment - This is a valid limitation. Digital imaging methods often require specific equipment, such as cameras or mobile devices, which may not be readily available in all settings.
E) Provides immediate results - This is not a limitation but rather an advantage. Digital imaging methods can offer quick results compared to some traditional dietary assessment methods.
F) Suitable for all age groups - This is not a limitation but rather an advantage. Digital imaging methods can be adapted for use across various age groups.
So, the correct limitations from the provided options are C, D, and potentially E, depending on whether immediate results are considered a limitation in a specific context.