Re: blood sugar during fast - how low is too low?

When patients undergo therapeutic fasts, blood Sugar levels below 50 mg per deciliter are not uncommon. As the fasters' blood Sugar dips to low levels, they may experience weakness and lethargy. Quite normal to have low blood Sugar as your body is burning fatty acids as a main fuel source which occurs after your supplies of glycogen have been exhausted after day 3 to 4.