"You don't have to train kids to like candy," said Nestle. "What I hear is that mothers find it hard to get kids to eat. Of course they aren't hungry because they have been fed so much and kids get used to eating sweet things."
Nestle also said the company's health claims are not backed up by definitive proof. Some research has lined DHA to visual and cognitive benefits in young infants, though long-term studies are lacking.
A recent report by the Institute of Medicine called for tighter standards on nutrition claims in light of the obesity epidemic and rising rates of type 2 diabetes among children.
Nestle, author of "What to Eat," said that when companies add "functioning ingredients" like lutein, lycopene and beta carotene to formulas, it increases cost.
These ingredients are "about marketing, not health," she writes on her blog, Food Politics.
Other companies have already been called to task for their health claims.
In December of 2009, the FDA forbid manufacturer Nestle from marketing Juicy Juice with DHA to help with "brain development." Under federal regulations, no products can make nutrient content claims if it is marketed for children under the age of 2.
"Her brain will triple in size by the time she's two," the company claimed in its marketing material.
General Mills Cheerios and Kellogg's Rice Krispies were also warned by the FDA about false health claims in their packaging.
"I am very surprised the FDA hasn't taken any action on this," said professor Nestle. "I don't see any difference between juice and this or an immunity claim on a cereal box."
ABCNews.com was unable to reach a spokesman at the FDA Enfagrow's health claims.
Perille said the company made no "inappropriate" health claims.
He defended the vanilla-flavored Enfagrow -- "a sippy cup product" -- which has the same calorie count and nutritional profile as the chocolate version, but is lower in sugar. Most of its 16 to 17 grams of sugar are from lactose, the natural sugar found in milk; 4 to 5 grams are added sugar.
"It's been on the market a year and is doing well with great testimonials," Perille said.
"It's positioned as a product as part of a balanced nutrition diet for toddlers, particularly beneficial when the toddler has an undiversified palate and narrow range of food and doesn't always get everything they might need," he said. "It's another choice or tool to potentially round out nutrition."
When infants are ready to be weaned, sometime after 12 months old, they are ready for nutritious table food, not formula, according to nutritionists, who encourage parents to expose toddlers to a wide-range of foods.
Dr. Keith Ayoob, director of the nutrition clinic at the Rose R. Kennedy Center at Albert Einstein College of Medicine, said products like Emfagrow are fine when used therapeutically for children with special medical needs and wasting conditions who have high caloric needs.
"At times we recommend them," he said, but warns against giving it to the "average picky eater.
"For a toddler, I would try everything else first," said Ayoob.
Food like eggs, milk, fruits and vegetables also support the immune system, according to Ayoob. "This is all about variety, and helping kids learn to eat and accept a variety of food. No one food can do everything."