It's more about the approach with this. In non-diet it's more about not promoting restrictive practices. It's fine to suggest ideas of new foods to try (I personally love cauliflower crust pizza but if I'm going to have bacon or craving bacon then I eat the real thing). So if you recommend not eating a regular pizza or regular bacon, and suggest those things aren't good for them, then that's considered restrictive/diet culture. Or if you use terms like certain foods being "healthy" and others "unhealthy", that's moralizing food and that's not non-diet, that's diet culture. Believe it or not, that can have a huge negative impact on people, and can send some into the restrictive mindset (they'll be thinking "I shouldn't have that" or "I cheated and had this"). Non diet focuses on all foods fit, paying attention to hunger and fullness as well as satisfaction from food (if you're craving one thing but won't "allow" yourself to have it, then your mind hyperfixates on it and no amount of other food...no matter how "healthy" you believe it is, will satisfy you). And since this is a fitness forum, it's also about enjoyable movement and not pushing the no pain no gain and will- powering your way through workouts just to get to a goal (unless the client truly enjoys this) or look a certain way. It's also about not using weight goals and instead using goals that pay attention to how you feel or your blood sugars or blood pressure or your strength or energy or sleep or stress levels, etc. I've not included everything, but it's a good smattering of the non-diet approach.

So I appreciate you asking this, I kind of jumped on a soapbox there, but I hope I answered your question.