Refined white breads are simple carbohydrates that your body processes as sugar, and can really hinder your weight-loss efforts. Whole grain bread, on the other hand, is chock-full of slimming fiber and can help you feel fuller, longer. Just be sure to read your labels. “If the ingredients at the top of the ingredient list read sugar, sucrose, fructose, corn syrup, white or wheat flour, these foods contain mostly simple carbs and should be limited,” Rebecca Lewis, RD, told us. “A food is only considered a whole grain if the first ingredient on the packaging says, ‘whole grain’ or ‘whole wheat.’”
The trick here is not only to avoid all obvious sources of carbohydrate (sweets, bread, spaghetti, rice, potatoes), but also to be careful with your protein intake. If you eat large amounts of meat, eggs and the like, the excess protein will be converted into glucose in your body. Large amounts of protein can also raise your insulin levels somewhat. This compromises optimal ketosis.