What are the Makruh Acts of Fasting?

Acts contrary to the meaning and purpose of the fast,  which might even break the fast if done excessively, are the makruh acts of fasting. Tasting or chewing, for example, are makruh because the possibility of swallowing it. Although it does not break the fast, treatments that weaken the body - like giving blood - are makruh while fasting. (Ilmihal, 406) The fasting person should avoid anything that could cause harm to the meaning of the fast.