re: No sugar, no flour

That is simply a low glycemic diet. You avoid refined, quick to digest carbs that raise blood glucose and insulin levels since that is causes accululation of body fat. Flour, rice, breads, potatoes, pasta, beer, etc. are avoided and replaced with mostly meat and fat including eggs, cheese, leafy greens, and other low glycemic foods. Atkins is one variation, and it works. It's not necessary to limit the meat and fat intake like diets that count calories. Read Taubes 'why we get fat, and what to do about it'.