You may decide to partner in some way with a diet service purely to increase your income from your fitness career, and your clients may succeed with these diet programs, however you should be aware that this may ultimately have a negative impact should the diet not yield good results or have a detrimental impact on your clients health. It is best to focus on sound time tested nutrition practices if your aims are to truly help your clients. The benefit to you will be good brand reputation that people know they can trust and can have confidence in.
You will be better served by providing a good stable nutrition plan for your clients and help them to understand not only the good healthy foods but also aspects of nutrition like protein and calories. Manage their expectations and try to educate them that what they see on social media is not realistic in normal daily life and can be very unhealthy.
Help them make meaningful long lasting changes as opposed to quick ‘fad’ diets where most people (as high as 98% in some descriptions) of people who diet using these diets in order to lose weight gain it back within 5 years; fad diets fail because many of them are not sustainable, and people revert to former eating habits when the diet fails.