Alledgedly it helps weight loss.
Carbohydrates are converted into energy, which is used by the body. This takes time.
If the body does not use the energy immediately (in exercise etc) it is then converted to fat and stored for later use as an energy store.
The theory is that if you eat carbohydrates after lunch time, it is more likely to be stored as fat when you sleep at night, than be burnt as energy through the day.
I said alledgedly at the start.
At the end of the day, if your calorific output exceeds your calorific input, you will lose weight, be it from eating carbs, protein, or fats