Diet composition of infants is of primary importance, especially in the early stages of life. Feeding has to fulfill babies' unique and rapidly changing nutritional needs. Breast milk always remains the ideal infant nourishment. However, considerable progress has been achieved in the composition and processing of commercial feeding formulas for infants and young children.


Thirty years ago, infant formulas consisted simply in largely unmodified powdered milk. Skim milk was used for infants before the age of 4 months, and whole milk thereafter. Advancement in food industry over the past few years has led to greatly improved infant formulas, now closer in composition to the unsurpassed reference, human milk.

• Starter infant formulas provide the right composition to meet the nutritional needs of infants during the first four to six months of life.
• Follow-up formulas are either weaning formulas or toddler formulas. Weaning formulas can be used as part of a diversified diet that is no longer exclusively milk-based. Toddler formulas are designed for young children from age one to three. Most starter infant formulas and weaning follow-up formulas are supplied as powders to be reconstituted with water, whereas nearly all toddler formulas come as ready-to-feed.

There are two different types of infant formulas:
  - unmodified protein content formulas: protein content ranges between 2.25 and 3 g/100 kcal, with a casein content close to cow's milk and consistently higher than 50% of total proteins.
  - adapted protein formulas: protein content may range between 1.8 and 3 g/100 kcal and the amount of soluble proteins must be equal to or greater than the casein's.

The composition of currently available formulas meets all the infant's nutritional needs. However, infant formulas, even adapted protein formulas, do not bear the same qualities as human milk (Table 1):

  - they do not provide the same immunological protection (immunocompetent cells, immunoglobulins, lysozyme, lactoferrin, etc.),
  - in contrast to human milk, they do not contain oligosaccharides, except for the higher homologues of essential fatty acids (docosahexaenoic acid - DHA; arachidonic acid - A.A.),
  - they do not contain specific ligands that facilitate the absorption of certain trace elements (iron, zinc),
  - they do not provide the infant with the close physical contact allowed by breastfeeding and essential to the child's emotional development.

* only lactose and malto-dextrin
** Gui. C:GUIGOZ CONFORT; PEL:PELARGON; LEM=LEMIEL; Gal Pre:GALLIA PREMIUM
M = mean
Table 1

FORMULAS WITH AN ADAPTED PROTEIN CONTENT :
APTAMIL, BIOGUIGOZ, ENFALAC, MATERNA spécial, MODILAC 1, NOVALAC 1, SMA classic.

FORMULAS WITH AN UNCHANGED PROTEIN CONTENT :
ALMA, BLEDILAIT, ENFALAC, GALLIA LACTOFIDUS, GALLIA, GALLIA PREMIUM, GUIGOZ CONFORT, GUIGOZ 1, LEMIEL, MATERNA, MILUMEL, NIDAL, NUTRICIA, PELARGON, SMA CONFORT.


Whether adapted protein formulas or formulas with unchanged protein content should be preferred remains open to debate. The modular protein content formulas seem to be superior because they contain a higher percentage of soluble proteins with a higher chemical score*. However, adapted protein formulas have not caught on in France as much as they have in other industrialized countries. This relative, and probably unfortunate, indifference may have several explanations:
  - such formulas seem to be associated with more frequent regurgitations, not readily accepted by mothers
  - their higher soluble protein content, in particular beta-lactoglobulin content, may promote the development of allergies.

* chemical score: a rating of the quality of a certain protein obtained by comparing its limiting amino acid pattern with that of a reference, in this case breast milk proteins.

Follow-up formulas are intended for children after the age of four to six months (weaning formulas) and for children one to three years old (toddler formulas) who have begun a diversified diet. These formulas are closer in composition to cow's milk than starter formulas (table 2). However, follow-up formulas differ from cow's milk in the following: they are enriched with essential fatty acids (achieved by replacing all or some of the milk fats by vegetable fats, as in infant formulas), they have a higher vitamin E content and they are fortified in iron and vitamin D. Weaning formulas are generally offered as unflavored powders (Table 2). With a single exception, toddler formulas are in a ready-to-feed form and are usually vanilla-flavored. Supplementation with essential fatty acids, vitamins and trace elements, especially vitamin D and iron, gives these formulas a definite nutritional advantage over the traditional UHT sterilized milks. Keeping in mind that the daily milk consumption (taken as milk or dairy equivalent) should not be less than 500 ml to ensure adequate calcium intake.

FOLLOW-UP FORMULAS
FORMULAS	WEANING FOLLOW-UP FORMULAS	TODDLER FORMULAS
Per 100ml
Powder (g)	13 to 16 (M: 14.7)	Liquids (except MATERNA)
Calories (kcal)	63 to 76 (M: 71)	63 to 71 (M: 66)
Protein (g)	2 to 3 (M: 2.3)	2.2 to 3.2 (M: 2.6)
Casein (%)	80	80
Lipids (g)	2.5 to 3.6 (M: 3.1)	2.4 to 3.5 (M: 2.8)
Linoleic acid (mg)	400 to 690 (M: 515)	210 to 540 (M: 390)
Linolenic acid (mg)	39 to 90 (M: 52)	38 to 100 (M: 58)
Carbohydrates (g)	6.2 to 9.1 (M: 8.1)	5.5 to 8.1 (M: 7.6)
Lactose (%)	42 to 88	41 to 100
Malto-dexterin (g)	0.7 to 4.9 (M: 2.3)	0 to 3.2 (M: 1)
Other sugars *	Starch: Gui. C. LEM*. Sucrose. Fructose. Glucose: LEM *	Starch : Mil * Sucrose: Gui. C. Nest*
Minerals (mg)	500 to 680 (M: 550)	520 to 800 (M: 670)
Sodium (mg)	19 to 43 (M: 33)	32 to 42 (M: 37)
Calcium (mg)	80 to 108 (M: 88)	95 to 111 (M: 102)
Ca/P	1.17 to 1.7 (M: 1.3)	1.2 to 1.57 (M: 1.3)
Iron (mg)	0.8 to 1.4 (M: 1.2)	1 to 1.4 (M: 1.2)

FOLLOW-UP FORMULAS
FORMULAS	Breast Milk
Per 100ml
Powder (g)	Liquid
Calories (kcal)	65
Protein (g)	3.7
Casein (%)	80
Lipids (g)	3.5
Linoleic acid (mg)	90
Linolenic acid (mg)	Traces
Carbohydrates (g)	4.5
Lactose (%)	100
Malto-dexterin (g)	0
Other sugars *	0
Minerals (mg)	800
Sodium (mg)	48
Calcium (mg)	125
Ca/P	1.25
Iron (mg)	0.03

*Gui.C : GUIGOZ CONFORT; LEM : LEMIEL; Nest : NESTLE JUNIOR;
Gui. PP : GUIGOZ Premiers Pas; Mil : MILUPA CROISSANCE
M = mean
Table 2

WEANING FOLLOW-UP FORMULAS :
ALMA, BLEDILAIT, ENFAMIL, GALLIA, GALLIA PREMIUM, GUIGOZ CONFORT, GUIGOZ 2, LEMIEL, MATERNA, MILUMEL, MODILAC (liquid or powder), NESTLE (liquid), NIDAL, NOVALAC, NUTRICIA, SMA 2.

TODDLER FORMULAS :
BLEDILAIT CROISSANCE (liquid), EVEIL (liquid), GALLIA CROISSANCE (liquid), GUIGOZ Premiers pas (liquid), MATERNA CROISSANCE (powder), MILUPA CROISSANCE (liquid), NESTLE JUNIOR (liquid), CANDIA CROISSANCE (liquid).


Soy-based preparations (BOX) :
In North America, the wide use of soy-based preparations (BOX) is supported by the fact that they carry less risk of causing allergy than cow's milk, although this issue is still questioned. In contrast, BOX are not as popular in France. These preparations also answer mothers who wish to limit (wrongly or not is debated) consumption of animal products, especially bovine. Considering the very stringent nutrient levels set for infant foods (specific standards for methionine, carnitine, iron, zinc, vitamin D, etc. content), commercially prepared infant and follow-up formulas available today (MODILAC-SOY, PROSOBEE, GALLIA-SOJA) certainly meet the nutritional requirements of infants and young children. It would be a mistake to believe the same applies to all soy-beverages, the so-called "soy-milks" sold in supermarkets. Replacing milk and dairy products with soy-beverages exposes young children to nutritional deficiencies. Hence, soy-based formulas are not recommended for use in children who are allergic to cow's milk, as cross allergies are not uncommon.

Available only on medical prescription, specialty formulas and milk substitutes are intended for use in a wide variety of pathological states and do not comply with the specifications set forth in administrative orders dated 1976, 1978 and 1994 (see box). Most are sold only in pharmacies, and some of them can only be purchased through a hospital pharmacy.

Formulas for premature and dysmature infants :
These specialized formulas are characterized by a higher protein and sodium content than infant formulas. In addition, they are enriched with medium-chain triglycerides, with vitamins (B9, C, D, and E) and also with higher homologues of essential fatty acids, such as D.H.A. and A.A.. The formulas are identified by the prefix "Pre-".

Pre-thickened "anti-regurgitation" or A.R. formulas :
They are intended for infants who suffer from regurgitation, a frequent problem at that age. Apart from the addition of a thickener, their composition is very similar to infant formulas. However, depending on the thickener, A.R. formulas may differ qualitatively (locust bean flour) or quantitatively (rice- or cornstarch) from infant formulas, and hence do not fall in the same regulatory category as foods for healthy infants.

Low-lactose content formulas :
Often advocated when oral feeding is resumed following severe diarrhea or recurrence of diarrhea (post-enteritis syndrome), several such formulas contain casein as the sole protein, while others contain soluble proteins and casein (HNRL, O-LAC, MODILAC without lactose). O-LAC, which contains absolutely no lactose, is suitable for the dietary treatment of congenital galactosemia.

Hypoallergenic formulas :
These so-called "H.A." formulas have reduced allergenic properties because they contain partially hydrolyzed proteins. When used exclusively during the first four months of life in infants with a family history of allergy, they reduce the risk of developing intolerance to cow's milk and atopic eczema. They are also recommended as temporary supplements to breast milk to prevent type I allergic reactions at weaning.

Hydrolyzed-protein formulas :
Hydrolyzed-protein formulas differ from H.A. formulas by containing even more hydrolyzed proteins, broken down to low molecular weight peptides of less than 3000 daltons. Most hydrolyzed-protein formulas contain no lactose and are reserved for used in very specific therapeutic indications: intolerance to cow's milk proteins, reintroduction of oral feeding following severe diarrhea or diarrhea before the age of 3 months, extensive small intestine resection (short-bowel syndrome). ALFARE, GALIAGENE PROCESS, NUTRAMIGEN, PEPTI-JUNIOR and PREGESTIMIL, PREGOMINE, are among these products. Some of them contain absolutely no galactose and can be used to treat congenital galactosemia.

Other milk substitutes :
Other formulas are designed for use in rare therapeutic indications. For example: 1) formulas consisting almost exclusively of medium-chain triglycerides (MCT); 2) formulas containing fructose as the only sugar; 3) low-calcium content formulas and 4) a full range of products that either contain with reduced levels of, or are entirely free from one or several amino acids. The latter are designed for the treatment of amino-acid diseases and organic acidosis (SHS, MILUPA, MEAD-JOHNSON therapeutic lines). Examples of such formulas are LOFENALAC, MAXAMAID XP, and PKU used for the treatment of phenylketonuria.

Considerable progress has been made in the composition, processing and form of formulas specially designed to meet the needs of infants and young children. Younger is the child, greater is the importance that milk holds in his diet, as is the importance of its composition to fulfill any special nutritional needs. Today, no dietary supplementation is necessary until the age of six months, other than 400 to 500 IU of vitamin D and 0,25 mg of fluorine. However, in spite of the improvements achieved in infant formulas, breast milk still is superior and irreplaceable.

Pr Michel VIDAILHET
Chief of Pediatrics - C.H.R.U. Nancy

BOX 1 :
Official french legislation regulates the composition of infant formulas. Administrative orders dated July 1, 1976 and March 30, 1978 define the criteria to be met by formulas intended for infants of 4 months of age and less, and those intended for older infants. The Administrative order dated January 11, 1994, that takes into account research outcomes of the past 20 years and applies the W.H.O. guidelines and EEC directives of 1991 and 1992:
* The use of the term "humanized" formulas is prohibited, as it may wrongly imply that certain infant formulas are comparable to breast milk.
* Routine vitamin D supplementation of these formulas is authorized.
* The term "formula" is restricted to those products that contain cow's milk whole protein. Soy-based products may be labeled "infant preparations" or "follow-up preparations" if they meet the limits set for these two categories.

Arrêté du 11/01/1994, relatif aux aliments diététiques et de régime de l'enfance. Journal Officiel, 15/02/1994, 2552-2559.

Comité de Nutrition. Acides gras essentiels et alimentation du nourrisson. Société Française de Pédiatrie. Arch. Fr. Pédiatr. 1988; 45 : 839-44.

Comité de Nutrition. Le fer dans l'alimentation du nourrisson. Société Française de Pédiatrie Arch. Fr. Pédiatr. 1980; 37 : 337-43.

Comité de Nutrition. Besoin en protéines des nourrissons et des enfants en bonne santé Société Française de Pédiatrie. Arch. Pédiatr. 1997; 4 : 373-82.

ESPGAN. Committee on nutrition. Comment on the composition of cow's milk based follow-up formulas. Acta Paediatr. Scand. 1990; 79 : 250-4.