Not true. Forcing your child to eat when he isn't hungry is a good way to encourage feeding problems in the future.
The best way to prevent feeding problems is to teach your children to feed himself as early as possible, provide them with healthy choices and allow experimentation. Mealtimes should be enjoyable and pleasant and not a source of struggle.
Common mistakes are allowing your children to drink too much milk or juice so that they aren't hungry for solids, forcing your children to eat when they aren't hungry, or forcing them to eat foods that they don't want. Also, avoid giving large amounts of sweet desserts, soft drinks, fruit-flavored drinks, sugarcoated cereals, chips or candy, as they have little nutritional value.
As a toddler, your child may start to refuse to eat some foods, become a very picky eater or even go on binges where he will only want to eat a certain food. An important way that children learn to be independent is through establishing independence about feeding. Even though your child may not be eating as well rounded a diet as you would like, as long as he is growing normally and has a normal energy level, there is probably little to worry about. Remember that early childhood is a period in his development where he is not growing very fast and doesn't need a lot of calories. Also, most children do not eat a balanced diet each and every day, but over the course of a week or so their diet will usually be well balanced.
While you should provide three well-balanced meals each day, it is important to keep in mind that most children will only eat one or two full meals each day. If you child has had a good breakfast and lunch, then it is okay that he doesn't want to eat much at dinner. Although your child will probably be hesitant to try new foods, you should still offer small amounts of them once or twice a week (one tablespoon of green beans, for example). Most children will try a new food after being offered it 10-15 times.
Other ways to prevent feeding problems are to not use food as a bribe or reward for desired behaviors, avoid punishing your child for not eating well, limit mealtime conversation to positive and pleasant topics, avoid discussing or commenting on your child's poor eating habits while at the table, limit eating and drinking to the table or high chair, and limit snacks to two nutritious snacks each day.
You should also not prepare more than one meal for your child. If he doesn't want to eat what was prepared for the rest of the family, then he should not be forced to, but you should also not give him something else to eat. He will not starve after missing a single meal, and providing alternatives to the prepared meal will just cause more problems later.