Is it permissible for a female nutritionist to write dietary programs for men, taking into consideration that she will not touch them, will ask questions, and weight will be measured by a scale?

There is no impediment for a female specialist to write nutritional programs for men, as long as her work does not involve viewing the patients' awrat (private parts) or touching them, and there is no khalwah (private seclusion). This is provided that she adheres to the legal hijab and limits her speech with patients to what is necessary, without softening her voice.