Hi no promises but there are a few things one can do. Of course height of a person should be taken into consideration in maintaining the proper level. Some things one can do: no meats, dairies, eggs, fats, sugars, desserts, sweets, or snacks. Lots of salads with a few nuts to increase satiety. There must not be much because the can add calories if there are many. Because nuts are a bit harder to digest it might keep a person from becoming hungry so fast. A peice of bread without fattening spread might be useful for satiety. One can learn to eat bread plain some people like it with a bit of tomato paste added and maybe a bit of lemon juice(without added citric acid)stirred into the tomato paste. If it has no additives this task is much tastier. Home made bread is perfect in my opinion if there is no baking soda and no shortening or hydrogenated fats added. A low sugar fruit salad might be served at a different meal.
The amount of the serving might be lowered until results desired are obtained. If one eats 3 cups now then the serving size might be changed to 2 cups. After measurements are done a few times an idea of about the amount needed may be done without actually measuring anything. A daily walk and more activity in the home and at work may be beneficial also. Recently someone said that a person uses 60 more calories standing than sitting.