Well, I've been nursing dd for almost 3 1/2 yrs so far and I do feel that diet plays a huge part in the way I feel. Sugar consumption has a lot to do with it and I try to stick to organic sugar and other wholesome sweeteners. Refined sugar and refined flour make you feel tired since they completely deplete your body of minerals and vitamins to be processed and they cause your blood sugar levels to swing wildly. So cutting out refined sugar is a great first step. But that's only part of the equation. I feel like the consumption of organic raw foods and wholesome fats do help a lot too. I take cod liver oil (Carlson's lemon flavored) and wheatgrass juice almost everyday. I also juice organic vegetables and eat raw nuts, avocados, raw cream and butter and olive oil. I try to consume organic meats (turkey and chicken) and I try to avoid farm-raised fish, which contains elevated levels of mercury and PCBs. I give preference to wild alaskan salmon, which contains lower levels of contaminants. However, I believe I do consume way too much grains and I'm totally addicted to carbs so there's a big difference in my level of energy depending on how I eat. Good luck!