You can use dietary to describe anything that concerns a person's diet.
Dr Susan Hankinson has studied the dietary habits of more than 50,000 women...
As with all dietary changes, reducing salt should be done gradually.
You can use the word dietary to describe substances such as fibre and fat that are found in food.
...a source of dietary fibre.
There is relatively little information about dietary, maybe you can watch a bilingual story to relax your mood, I wish you a happy day!