The Protein Power Diet allows all types of meat, fish, poultry, eggs, cheese, nonstarchy vegetables, butter, oil and salad dressing. It also allows alcohol in moderation. Foods that are avoided on this diet include fruits, starchy vegetables, grains and milk.verview. High-protein, low-carbohydrate diets are popular ways to lose weight. But according to the Mayo Clinic, high-protein diets can be difficult to maintain, do not always support long-term weight loss and can be unhealthy.