Dietitian: It is true that nutrients are most effective when provided by natural foods rather than artificial supplements. While it is also true that fat in one' s diet is generally unhealthy, eating raw carrots (which are rich in beta carotene) by themselves is nonetheless not an effective means of obtaining vitamin A, since the body cannot transform beta carotene into vitamin A unless it is consumed with at least some fat.
The statement 'fat in one's diet is generally unhealthy' plays the role of being mentioned as a reason for adopting a dietary practice that the dietitian provides a reason for not carrying to the extreme in the dietitian's argument.