The opening between guard (pores) cells is known as stomata. The stomata helps in diffusion of atmospheric CO2 into leaf's interior and also involved in loss of water by plant leaves through transpiration. The opening and closing of stomata is controlled by guard cells.
Guard cells control the opening and closing of stomata by becoming turgid or flaccid because of potassium ions. The water potential decreases by increasing the solute concentration and water always flow from higher potential to lower potential. Remember maximum water potential is zero.
When potassium ions concentration increases inside the guard cells, water follow the potassium ions and guard cells become turgid which cause the opening of stomata. On the other side when the potassium ions concentration decreases inside the guard cells the water leaves the guard cells and guard cells become flaccid causing closing of stomata.
Because there are several factors that determine weight loss or gain and reducing calorific intake is just one of them (for reducing weight loss). Other factors that should be considered is exercise. Doing regular exercise ensures that the metabolic rate of the body is increased so much of the calories are burned even after intake. Having a lower metabolic rate can result to increased weight gain even with low calorie intake.
