Those who are naturally slim behave in a different way from those who are overweight, in the presence of food. The naturally slim only eat what the body needs. When their nutritional requirements have been met they are satisfied.
For those who are overweight, their sensations of hunger and satisfaction are greatly affected by other things than the body's actual needs, e.g, if the food is delicious and tempting they continue to eat. However, it is also easier for them to refrain from eating if it is not, and this situation can be used to solve your problem. Make delicious low calorie wholesome food which you can eat plenty of without gaining weight. At the same time serve less attractive high calorie food which doesn't attract you. In this way you confine yourself to the delicious food, but the children can eat both. In my family we make tasty salads and soups for everybody and serve plain bread or rice to those who need more calories.
You needn't worry that the children won't eat enough, because they will go on eating until satisfied. Naturally slim people always eat what they require without having to think about it.
People with an overweight problem have difficulty in regulating their eating so that it follows the body's needs. It is therefore important that this difficulty is not passed on to the next generation; but by providing a diet consisting of delicious low calorie wholesome food and less attractive calorie rich food you reduce the risk that your children will take it over.