A low-carb diet restricts your intake of sugars, starchy vegetables, breads, pasta, grains and cereals. A no-carb diet, however, disallows all carbs, even trace carbs from fibrous vegetables, most cheese and condiments. The menu includes a variety of meats, offal — organ meat — and fat, making it extremely challenging to be completely zero-carb and get all the nutrients you need. A week is unlikely to leave you nutritionally deficient, but always check with your doctor before starting such an extreme plan. You will experience side effects from a no-carb regimen, especially if you are accustomed to eating a fair number of carbs.