For those without weight problems eating is controlled by the need for nutrition. Hunger comes when the stomach is empty and the blood sugar level sinks. When food has been eaten the blood sugar level rises again, satisfaction is felt and eating stops.
This automatic process doesn't work for you. Research on those who are overweight has revealed that they eat more when they have food around them and are stimulated by seeing, smelling and hearing talk about food. However, the research also revealed that when they don't have food around them and are not stimulated to eat, they find it easier to manage without food than those of normal weight.
Often it is possible for overweight people to learn to be hungry in the normal way, i.e., to have a normal hunger awareness caused by the body's needs, but if it can't be done they have to adapt to their handicap.
Always make sure that you never have the kind of food at home which encourages you to overeat. In your case you could exchange butter for olive oil, sugar for artificial sweetener and make porridge from buckwheat instead of oats. Proceed by trial and error and find which food you can have at home. Greens, root vegetables, fish, unpolished rice and buckwheat usually function. Never have ice cream and other attractive food in stock for guests, but if you must, then buy it just before their arrival if possible and not more than is required for them. If some is left over ask the guests to take it home, or throw it away.