I think the above statement is false. I believe people use sugar substitutes and fat replacers for the purpose of helping control their weight, to limit the symptoms and risk of conditions such as diabetes, cardiovascular diseases adn cancer and to prevent tooth decay, the subject of whether the two helps in the indicated is debatable. However, current research does not show that they help people reduce calorie intake or prevent obesity.
The substance that would be added in order to reverse the reaction would be any substance that is found in the product side. Adding a substance that tends to be a product will shift the equilibrium of the system and will allow the reaction to produce the substances that is found in the reactant side.
It happens during the s phase