What it is
Milled rice and water, naturally sweet and thin — the hypoallergenic option for people avoiding soy, nuts and dairy. Almost no protein.
Why your biology objects
Essentially liquid hydrolysed starch — very high glycemic and ~1g protein a cup, a glucose spike with nothing to slow it. It also concentrates the inorganic arsenic rice pulls from paddy water, which is why UK and Irish regulators advise not giving rice drinks to children under ~5.