When a child has eaten enough, it is pointless trying to push more food in. Next time you eat a meal, when you feel full, ask your partner to try to shovel more food into you. He or she can use the traditionally persuasive 'choo choo train' or 'aeroplane' methods and should not take 'no' for an answer. You will get pretty angry too. Encouraging children to eat once they are no longer hungry may also be an important cause of obesity in the long term.
Many children have a large drink just before meals.
It is no surprise if they then have no appetite. Many parents forget that sweets and snacks given to keep the child quiet can dull the appetite for the next meal. Discipline Toddlers are natural rebels and this is probably the single most important factor. Parents often invest a lot of time, love and energy in producing a meal and children can get a tremendous reaction if they then refuse to eat it. Important though it is, I feel certain that there are better times than mealtimes to make discipline an issue.