"Specific dietary restrictions" refers to limitations on the types of food or drinks that someone is allowed or able to consume due to health, religious, cultural, or personal reasons. Full definition
The protein is also dairy and gluten free so it is particularly useful to those with specific dietary restrictions. (blog.nkdnutrition.com)
We mostly stuck to standard breakfast fare, but because the new mom has some pretty specific dietary restrictions, we made sure the menu featured plenty of things she could enjoy, including these muffins. (mayheminthekitchen.com)
These amounts are also referring to healthy adults, and not necessarily someone who has a disease or condition which requires them to follow specific dietary restriction, such as those with chronic kidney disease who may need to limit their protein intake or someone with high blood pressure who it is recommended limit their sodium intake to 1,500 mg per day. (ellenratliffrd.com)