It would be interesting to know what factors make you react badly to a diet that you know is safe for you. So far JamesIV and gbol mentioned consuming carbs according to physical activity, tyw talked about circadian rythm and insulin sensitivity (eat most carbs earlier in the day) as well as intermittent fasting. I have noticed that a single stressed and non-optimal night will make me feel like crap and have zero energy (+ moody etc..) after breakfast, probably the same after lunch and then things may improve. Regular physical activity and not sitting too much help. Eating lunch a bit late can be a huge burden, so can not eating enough fat with a high carb meal. On a similar topic there are still times when I don't understand why the body reacts in a negative way, which makes me wonder how optimal can things get with just a controlled diet and a good environment.