Yes, why not? What about Isaiah? Is it not scripture?
Isa 58:5 Is it a fast that I have chosen, A day for a man to afflict his soul? Is it to bow down his head like a bulrush, And to spread out sackcloth and ashes? Would you call this a fast, And an acceptable day to the LORD?
Albert Barnes on this passage...
A day for a man to afflict his soul? - Margin, ‘To afflict his soul for a day.’ The reading in the text is the more correct; and the idea is, that the pain and inconvenience experienced by the abstinence from food was not the end in view in fasting. This seems to have been the mistake which they made, that they supposed there was something meritorious in the very pain incurred by such abstinence. Is there not danger of this now? Do we not often feel that there is something meritorious in the very inconveniences which we suffer in our acts of self denial?
John Gill...
a day for a man to afflict his soul? only to appoint a certain day, and keep that, by abstaining from bodily food, and so for a short time afflict himself; or only after this manner to afflict himself, and not humble himself for his sins, and abstain from them, and do the duties of justice and charity incumbent on him:
Here is an example of David fasting...
2Sa 12:17 So the elders of his house arose and went to him, to raise him up from the ground.
But he would not, nor did he eat food with them. 2Sa 12:18 Then on the seventh day it came to pass that the child died. And the servants of David were afraid to tell him that the child was dead. For they said, "Indeed, while the child was alive, we spoke to him, and he would not heed our voice. How can we tell him that the child is dead? He may do some harm!"
2Sa 12:19 When David saw that his servants were whispering, David perceived that the child was dead. Therefore David said to his servants, "Is the child dead?" And they said, "He is dead."
2Sa 12:20 So David arose from the ground, washed and anointed himself, and changed his clothes; and he went into the house of the LORD and worshiped. Then he went to his own house; and when he requested, they set food before him, and he ate.
Esther...
Est 4:16 "Go, gather all the Jews who are present in Shushan, and fast for me; neither eat nor drink for three days, night or day. My maids and I will fast likewise. And so I will go to the king, which is against the law; and if I perish, I perish!"
One fasts and humbles oneself by not eating or drinking, by afflicting one's soul. Eating and drinking is not fasting.