It will help you, it will also help you to go on a raw diet. It will be better if you go on a fruit diet, specially for detox.
theres some types of fasts: juice fast (grapes or lemons), water fast, dry fast. They are all effective, some ppl say dry fast is the best but grapes fast will supply energy while you detox.
What these does is cleanse your kidneys so you can filter more waste. You also need to make sure your adrenals are good. Stress affects adrenals. Therefore a fast that is on meditation on god will definitely heal you while a stressing life with processed foods, meat, dairy, eggs and grains will sicken you.