Which observation indicates a patient is emaciated during a physical examination?

The observation that indicates a patient is emaciated during a physical examination is marked weight loss suggesting malnourishment. Emaciation is characterized by a significant decrease in body weight due to the loss of fat and muscle mass, which often results from inadequate nutrition and can be indicative of an underlying health issue. Clinicians look for signs of malnourishment, such as a notably thin appearance, prominent bones, and a lack of subcutaneous fat, which are all consistent with marked weight loss. Assessing a patient's nutritional status is critical in emergency settings to identify those who may need urgent intervention or nutritional support.

The other observations do not provide evidence of emaciation. For instance, being well developed and well nourished indicates good health rather than malnourishment. A patient who shows no distress may simply be comfortable but does not necessarily reflect their nutritional status. Being alert and responsive indicates adequate cognitive function, but again, does not comment on the physical condition regarding weight and nutritional deficiency. Therefore, marked weight loss is the clear indicator of emaciation in this context.