I think some become tired also because of getting a nutrition disturbance when changing their diet totally not knowing enough of nutritions and maybe therefor not getting the right amount of all the different nutritions..
F.x. do bread have a lot of vitamin B´s that are essential for nerve and skin and the body´s wellbeing in general...
Also a lot of trace-minerals is in the wholemeal and oat which also contains the very highly needed magnesium which is used in about 230 different reactions in our body ..
And when stopping eating lots of root-vegetables and fruits one can easily become insufficient in potassium ... both a lack of potassium, sodium and magnesium can make people feel extremly tired and like all energy has left them...
Another problem can be a very low level of vitamin C if one eats mostly meat animal fats and diary products and not very much vegetables and no fruits...
vitamin D insuficiency also can make people extrmely tired and depressed, and it is not dangerous to take a supplement every day of a vitamin D ... like in vintertime 35 mikrograms a day
But it is important to get ones blood tested before taking those supplement in very high doses... so go to you GP before starting taking high amounts of nutrients except form the ordinary multi-vitamin... and ask specifically for test of electrolytes-numbers in your blood... and for the numbers of iron and vitamin D too.
Sodium the lack of sodium can become a problem when one change into eating almost only natural non-rafined foods which are not added sodium before we buy them.... and if one does not use sodium very much in cooking... but be aware most do actually get a little or very much to much sodium in their daily intake of foods..
About half a little teaspoon a day is what most need...but we are in general told as type 2´s not to use salt/sodiumchloride.... but like most other essential minerals ( and electrolytes like magnesium, potassium,sodium and chlorid ) vitamins and traceminerals one can both get too litlle and too much.
Another problem like what you maybe think is your problem is that maybe not everyones brains are equally good at funtioning with low levels of carbs..., but instead of going back to normal almost unlimited amounts of carbs one could just add like 5 grams of carbs every 2-3 hours so the carbs are in your blood most of the day and do not come only at one or two meals... thats where maybe half a piece or a quarter of a piece of fruit in between meals could be a good idea... so the amount is low enough at one time to not spike even though it is the very forbidden fruit...
Also a lack of vitamin B12 can make people feel extremely tired, and it is very dangerous to lack that vitamin because the kind of nerve damages is very similar to and can be neuropathy and other nerve damages that are ireversible. metformin can hinder the uptake of vitamin B12 mostly in the longer run, but WHO knows excactly when that problem occurs in each individual... if one can not uptake it in large doses, ine has to have it through injections.. if one eat a lot of meat and eggs and dairy then usually one gets enough of B12 , but of cause not if metformin hinders one in taking it up from the intestines.
Also iron deficiency can make people feel extemely tired... but if one eats lots of meat , especially red mest it is not likely one lacks iron... but what many do not know : you can not uptake iran from the meat it there is no vitamin C in the same meal as the iron rich foods..
But as we eat low carb in so many different ways it is very important to know something about nutrients, the daily amount needed of each kind and what would be the typical nutrient deficiency in the different low-carb styles...
Well thats my thoughts about this very very extreme tiredness that is actually a very wellknown problem too diabetics ...
One day i think we´ll be able to buy slow release pill of carbs... so that the spikes can be avoided totally... even slower release than highfiber-carbs or highfat-coated-carbs...
