EATING BEHAVIORS IN CHILDREN
OBJECTIVE NUTRITION 71, (MARCH 2004)
by Prof. Daniel RIGAUD, University Teaching Hospital Le Bocage, Dijon, France

To eat a “varied” diet, a biological requirement of omnivores, children must be taught to select what is good or what is bad for them.  And yet, very few biological signals provided them with such information.  Although humans are programmed to satisfy their hunger, what they eat and how they do so are almost entirely learned.  Consequently, eating fulfills three requirements: feeding, socializing, and pleasing oneself.  Faced with this complicated behavior, therapists cannot be content with simplistic answers.  They must aid children in structuring their behavior by looking for what pleases them and by developing their personalities.

SETTING UP AN EATING BEHAVIOR

Eating requires much learning

The structural development of eating behaviors in children follows two steps:  dependence and self-sufficiency.  Up to about the age of two years, children are not capable of satisfying their needs by themselves.  Therefore, they remain in a phase of affective and trustful tolerance (“Mom is right, she knows best”).  They do not have a choice and must rely mainly on their metabolic and affective needs.  They are also able to experience desire and pleasure.  Beyond the age of two to three years, children enter a phase of growing self-sufficiency.  They can choose, because they can remember, make connections, walk, open the food pantry, put things in their mouth etc. Since they know how to choose, they must choose, which give them their  “self-identity”.  Faced with their choices and their mother’s response to these choices, they are going to develop their own personality: to be sure that it is their own choice, sometimes it is necessary that children be opposed to their mother’s choice.  It is by saying “no” that children learn to define themselves with respect to their environment.  Thus, they build their personality.  In this regard, eating is an identifying act.

The setting up of an eating behavior in children occurs very early, undoubtedly starting with the first weaning.  It then develops according to three different periods: diversification of the diet and weaning from breast-feeding, “emancipation” of the child (self-sufficiency) and then in adolescence rejection of what is  “childish”.

Infants already know what satisfies them and what is good: they turn their head towards a smell they like, their facial expression and the sounds that they make express their pleasure or distaste.
It is important to note that milk is liquid and is low in energy;  moreover, infants have little ability to extract the carbohydrate and lipid energy contained in their energy stores (due to immature tissue lipase).  Therefore, infants can hardly “wait” more than three to five hours between feedings (breast feeding or bottle feeding). Consequently, they must fill their stomach to capacity.  This is why regurgitation is so frequent.  It is suggested that this type of sensation is perhaps sought after by some patients with binge eating.

Adjustment to metabolic needs

Children learn early on the nature of their metabolic needs and the quantity that they must ingest to meet them.  Therefore, infants learn to drink two times more from a bottle that is half as concentrated.  Adaptive anticipation is possible early on without cognitive knowledge : infants, two to three years of age who have been receiving a given desert for four days, will proportionately reduce the amount meat and starchy foods that they ingest before this desert.  This is selective appetite.  Children three to five years of age, subjected to a new diet and activities in the afternoon, first eat at noon depending on their hunger, that is, in response to the previous parameters.  But, starting on day 4, for they will eat according to the activities and the times of the following meal.  Therefore they can memorize a set of actions and adjust their eating behaviors.
This coverage of metabolic needs is very accurate.  It involves many signals incorporated in different neurons in the hypothalamus, some of which drive the sensation of hunger while others turn off this sensation, that is, producing satiety.  Short-term mediators respond both to cerebral as well as digestive stimuli: they are of energetic (glucose, amino acids, calories), motor (gastric emptying driven by motilin, cholecystokinin), or neurosensorial (neuropeptide Y) in nature.  In the longer term, they tend to be hormonal such as leptin, a hormone secreted by adipose tissue, which acts via an effector, NPY.  These elements are all incorporated by conditional learning in order to be readily available.  Nevertheless, it is also necessary to activate effectors of motivation ( “I am hungry enough to open the refrigerator”) and muscle mobilization.

HEDONISTIC NEEDS

It is not known very well what “pleasure” is for brain cells which gives this message:  the sensation of pleasure is associated with relaxation (“I feel well”, “I feel satisfied” is the contrary  of “I am tense”) as well as the notion of a preferred circuit (“I return to it”).  But with learning and self-worth (thus in the eyes of others), another type of circuit is set up, excitatory in nature: I give myself pleasure because it excites me (racing, championship, a contest, examination, work).  “Pleasure” circuits involve two opposite dimensions : an opioid system (beta-endorphin, in particular) which tends to provide the brain with greater relaxation; and the amphetamine and serotoninergic system , which guide to greater excitement (tension, stress).  This is probably why children who tend to prefer conditions of excitement (little sleep, agitation) have a tendency to become anorexic while children who tend to be calm (and thus promoting relaxed conditions) may tend to eat more.
When repeated, pleasure generates both its reinforcement and its opposite.  Infants deprived of food suffer (from hypoglycemia).  They call their wet nurse and thus their stomach is filled with a smooth and mild liquid, slightly sweet: milk.  They are completely satisfied!  But they ”spend their energy” and when energy stores become depleted, they again experience hunger, “withdrawal”. They call and cry and once again they are satisfied.  Repetition of this process, excitement-relaxation, leads to conditioning: this “withdrawal” which will be satisfied transforms into… desire.  But, if children feel that this desire encounters another feeling in the other person ( the one feeding them) or if they do not learn that what is missing is systematically satisfied, they will become worried and never become full.
Older children must learn to control their desire, in order to postpone their pleasure.  They also have to learn to end their pleasure, before distaste or dependence develops.  In adolescence, the need to look for pleasure is part of transgression “No, my appetite will not have any limits”. This is why addictive behaviors are more common at this age rather than before or after.

BETWEEN PERSONALITY AND DESIRE TO BELONG TO A GROUP

Eating has an identification function.  Starting at the age of 18 months, children  want very much to be like adults, whose gestures, behaviors and eating habits they copy.  It is here that their self-image intervenes between the cognitive and affective poles.  Children learn very early on to decipher their mother’s feelings and moods when they are eating: they give themselves pleasure or anxiety.  They will adopt a given behavior for a given circumstance.  Children diversify their diet not so much based on physiological needs (which are real) but to please their “food provider” and their peers.  It is an arduous undertaking for them.  A small mammal which is fed without “animal warmth” (relaxation) subsequently develops abnormal eating or non-eating habits.
Other children and many adolescents adopt gregarious attitudes and behavior of rejection, or even risk behaviors in terms of diet.  Adolescents seek an identity which differentiates them from their parents and their childhood by belonging to a group.  But they become anxious when faced with the unknown and they look for reference points, hence, their desire to do as their friends do, to eat like certain movie stars.  In the event of anxiety, they may conversely wish to “seek refuge in an eating behavior”, either by eating nothing (anorexia nervosa) or by episodes of bulimia or binge eating.
What this behavior encounters two physiological realities: eating fatty food, this is what gives taste to food and makes it possible to not be hungry during the hours of sleep (prolonged fasting).  There is a strong contradiction: “Fat is good” (for the palate); “fat is bad and harmful (for society and for health).
A dichotomous thought arises out of fear and places children in major contradiction: what I want or need is bad.  Feeding this contradiction is the last thing to do when one wishes to change a child’s eating behavior.

CONCLUSION

Eating fulfills three requirements: providing nourishment, socializing and pleasing oneself.  None of these can be excluded.  Obese children who say “I don’t eat anything” are not saying that they do not ingest anything, but that their social, hedonistic ( pleasure) and metabolic references have been distorted by a low-calorie diet.
A Chinese wise man once said : if you live near the sea, do not seek to build a wall so that your children do not drown, but instead teach them how to swim!

Pr. Daniel RIGAUD
University of Medicine and Hospital Le Bocage, Dijon