Baby food secrets: Understanding your infant’s reactions to new foods and flavors

© 2009 Gwen Dewar, Ph.D., all rights reserved

Babies sometimes act like they have very strong opinions about food. What’s going on in their heads? Do they truly hate green beans? Or love rice cereal?

Do babies prefer bland food, or do they like certain spices? Do babies experience flavors in the same way that adults do? Do they perceive things that we don’t?

Fascinating research offers answers. For example, experiments suggest that baby food preferences may start in the womb. There is also evidence that babies become accustomed to food flavors that they encounter in their milk or formula. 

We know, too, that children are influenced by the behavior of demonstrators. When they see someone else eating a food, it can make them more accepting of it (Addessi et al 2005).

And no — babies don’t necessarily prefer bland food. They don’t even prefer bland breast milk! In an experiment on 3-month infants, Julie Mennella and her team asked lactating moms to eat garlic and then watched how their babies responded.

When the garlic reached its peak concentration in their mothers’ breast milk, the babies suckled longer at the breast (Mennella and Beauchamp 1991).

So science can help us better understand our babies reactions to food. Here are some tips for making sense of your baby’s table manners.

(Looking for information about starting your baby on solids? For help with that, see my other article, “How to start babies on solid food.”)

Introducing new foods: Don’t give up just because your baby makes a funny face!

This seems to be one of those cases where Grandma was right: Babies really do make all sorts of funny faces when they try a new, solid food—even when that food is destined to become a favorite.

In an experiment on infants just beginning the transition from rice cereal to other forms of baby food, researchers recorded the facial expressions of babies tasting pureed green beans for the first time (Forestell and Mennella 2007). These were the most common reactions.

  • 95% of the babies squinted
  • 82% waggled their brows
  • 76% raised their upper lips
  • 42% wrinkled their noses

Such responses look like disgust or distaste, and indeed the expressions were related to baby food acceptance. The more infants squinted, the more slowly they ate.

But here’s the important point: They got over their initial dislike for green beans. It just took time.

Researchers asked the babies’ mothers to try feeding the infants green beans every day for 8 days in a row. The daily exposure wasn’t forced feeding. Each daily session consisted of a mom offering green beans to the baby until he had either rejected the food three times (by turning away or pushing the spoon back with his hand) or finished the jar. At the end of 8 days, babies were eating three times as much pureed green beans as they had in the introductory session.

Interestingly, though, their mothers couldn’t tell. Researchers asked moms to rate how well their babies liked green beans–both before and after the 8 day exposure program. The mothers’ assessments didn’t change. Perhaps that’s because babies continued to make funny faces while they ate.

So it seems that parents shouldn’t be overly deterred by a few screwball facial expressions. With daily exposure—even if it’s only three little tastes—your infant may come to accept a new baby food.

What about fruit? If you give infants sweet foods, won’t it spoil their appetites for other kinds of baby food?

Actually, there isn’t any experimental evidence for this idea. On the contrary, experiments suggest that children will learn to like a new vegetable more if their first experience with the vegetable is associated with sweetness (Havermans and Jansen 2007).

For this reason, half the babies in the green bean study were given peaches after each session with green beans. And that proved to be important, because

“…only those who experienced peaches after green beans seemed to like the taste of the green beans more after exposure” (Forestell and Mennella 2007).

Why should a sweet second course improve a baby’s liking for vegetables? I suspect it’s a question of fooling the baby’s system of postingestive feedback.

Postingestive feedback is how food makes us feel after we’ve begun to digest it, and this information can lead to rapid, automatic learning.

If we associate a food with pleasant sensations–like feeling full or satisfied–we tend to like it.

If a food leaves us feeling hungry, we will be less enthusiastic.

And if we feel sick or uncomfortable after eating, we may develop an immediate dislike for the food’s odor and flavor.

So perhaps the babies who ate green beans in a “stand alone” manner (i.e., without peaches as a second course) were more likely to notice the relatively poor energy return associated with green beans.

By contrast, the babies whose green beans were paired with peaches were probably more satisfied after each meal. As a result, they developed a stronger liking for green beans.

But does this mean I should force my baby to eat?

No. There are many reasons not to force feed babies. At best, it’s an exercise in futility. When people are forced to eat a food, they come to like it less, not more. And at worst, you might be forcing your baby to eat something to which he is allergic or sensitive.

So how can I tell if a baby truly dislikes something?

The key, I think, is what the baby does when you try to put food in her mouth. If she turns her head away, or pushes away the spoon, or gags, she’s done with that particular baby food. At least until tomorrow, when—like the babies in the green bean experiment—she can try it again.

What about a baby’s sense of taste? Is it possible that babies perceive flavors differently than we do?

Yes, I think so.

Our sense of taste is influenced by two sources of information.

1. Our taste buds detect the primary tastes–sweetness, sourness, bitterness, saltiness, and umami, a savory, hearty taste associated with glutamate and found in meats, milk products, and mushrooms.

2. Our sense of smell permits us to distinguish all the other, more complex flavors—like garlic or cumin or cinnamon.

Experiments reveal babies have a well-developed sense of smell at birth. And newborns can detect sweetness, sourness, umami, and some bitter flavors. The ability to detect saltiness comes later, at about 4 months (Beauchamp et al 1986).

But this doesn’t mean that your 4-month old experiences flavors in the same way that you do. As many parents can attest, babies may stubbornly reject foods that seem perfectly acceptable to adults. There are several possible reasons for this, and you can read the details in my story about the science of picky eaters.

But the quick version is:

  • Over the years, you have learned to tolerate bitter and sour flavors that are initially aversive
  • Babies might be more sensitive to bitter flavors
  • Babies might be “prewired” to detect and prefer the sweetest foods, because sweetness is a cue for higher energy content
  • Even after you control for age, some individuals have a genetically-based, heightened sensitivity to bitterness.

So, despite your best efforts, your baby might reject some foods no matter what you do.

Other ideas: Make your own baby food

As noted above, commercially-prepared baby food is often lacking in seasoning. If your baby craves a little of the flavors he encountered when he was gestating or drinking breast milk, you can always try making your own babies foods at home.

For inspiration and recipes, check out Baby Food 101, by Lisa and Matt Cain. This website includes a variety of helpful information, including nutritional facts and suggestions about which ingredients are best purchased in organic form.

References: Baby food

Addessi E, Galloway AT, Visalberghi E, Birch LL. 2005. Specific social influences on the acceptance of novel foods in 2-5-year-old children. Appetite. 45(3):264-71.

Beauchamp GK, Cowart BJ, and Moran M.1986. Developmental changes in salt acceptability in human infants. Dev. Psychobiology 19:17-25.

Beauchamp GK and Mennella JA. 2011. Flavor perception in human infants: development and functional significance. Digestion. 83 Suppl 1:1-6.

Forestell CA and Mennella JA. 2007. Early determinants of fruit and vegetable acceptance. Pediatrics 120(6):1247-1254.

Havermans RC and Jansen A. 2007. Increasing children’s liking of vegetables through flavour-flavour learning. Appetite. 48(2):259-62.

Mennella JA, Beauchamp GK. Maternal diet alters the sensory qualities of human milk and the nursling’s behavior. Pediatrics 1991;88:737-744

Mennella JA, Nicklaus S, Jagolino AL, and Yourshaw LM. 2008. Variety is the spice of life: strategies for promoting fruit and vegetable acceptance during infancy. Physiol Behav. 94(1):29-38.

Mennella JA, Trabulsi JC. 2013. Complementary foods and flavor experiences: setting the foundation. Ann Nutr Metab. 60 Suppl 2:40-50.

Ventura AK and Worobey J. 2013. Early influences on the development of food preferences. Curr Biol. 6;23(9):R401-8.

Content last modified 4/9

image of baby in high chair © Rodrigues