Low carb diets are not really a diet, it is a lifelong, sustainable lifestyle. The foods we eat on a low carb diet are whole foods, natural, and not processed by a factory, so they do not contain preservatives or additives to make it last longer on the shelf.
They are foods provided by nature that we as a species have evolved and thrived on. Animal products in particular, are very nutrient dense foods, therefore a diet high in animal products will ensure all the nutrients we need for a healthier life, growth and disease reduction. Carbohydrates are not an essential nutrient for the body, and they are used solely as a source of energy. Certainly foods that contain carbohydrates also have other nutrients, but often the nutrient density is poor due to the processing and gene modification of these foods.
These nutrients can be obtained from other more natural sources, in much greater amounts, making these processed foods not essential. When you are eating a LCHF diet, you will not need to take many of the other supplements people buy because of poor nutritional value in their food. The only supplements required are extra salt, magnesium and potassium.