My green juice contains 40% apple and pear. This way I think it's suitable for breaking a fast. I agree with Archus that pure green stuff might be unsuitable for a resting stomach. I would still use my bottled juice only in case of emergency. I have a nice cold press juicer and going to juice grapes, apples, pears and pineapples as a first step with some greens like cucumber and bell peppers.