Final answer:
The most important factor to first assess when developing a weight reduction plan for an overweight patient is the patient's social, emotional, and behavioral influences on obesity, as this will inform a personalized and effective intervention strategy.
Step-by-step explanation:
In developing an effective weight reduction plan for an overweight patient who expresses a willingness to lose weight, it is most important for the nurse to first assess the patient's social, emotional, and behavioral influences on obesity (C). This involves understanding the personal habits, psychological factors, and environmental circumstances that contribute to the patient's weight issues. A comprehensive assessment of these factors is essential for creating a personalized and sustainable weight loss strategy that addresses the root causes of their obesity.
Anthropometric measurements such as BMI and skinfold thickness are also important as they provide objective data regarding the patient's weight status (D). However, without understanding their behavioral patterns and emotional states, it might be challenging to facilitate the necessary lifestyle changes. Physical activity level (B) is a component of lifestyle that will be important to address, but not before assessing the underlying behavioral influences.
Moreover, the length of time the patient has been obese (A) can provide insight into the chronicity of the condition, but it does not directly inform the development of an intervention plan. Successful weight loss strategies will often involve behavioral interventions, nutrition education, physical activity goals, and necessary lifestyle changes tailored to the patient's specific situation.