A low-fat diet is a type of diet in which you have to restrict your fat under 10% calories. The most interesting thing is that in this diet you don't have to avoid carbs unlike in keto diet. In this diet, you have to limit your protein intake to under 10% calories. We all know the majority fat source is animal protein.  That's why in this diet you have to avoid animal-based protein like meat, fish, beef, etc. Plant-based oil sources such as soybeans oils, nuts oils, virgin oil which is considered as a healthy source of oils are also avoided in this type of diet.