The nutrient is the need that may be changed by the change of environmental conditions and by or by gender.

INFANT NUTRITION:

The nutrition required during the first year for the baby, where a healthy balanced, and adequate diet is required to fulfill all the requirements of a baby, i.e.
a. To provide energy to creep, crawl, play, learn, gurgle, and smile
c. Good health is the key to happiness all through life right at the start.
Mother’s milk is considered the primary food for infants. It is not only the best but also a must for the infant. It contains all the essential nutrients the infant requires in the proportions necessary for growth. Breast milk is a natural gift, specially manufactured for the infant. It is easy to digest and contains a nutrient balance for the infant’s needs. It protects against the development of allergies and provides antibodies to the baby to strengthen the immune system against infection. This factor encourages the growth of Lactobacillus, which depresses pathogenic organisms’ growth. Mother’s milk is inexpensive, convenient, sterile, and at body temperature. It discourages overfeeding. It establishes a close, loving mother-child relationship. The mother has additional benefits as hormones are released when a baby sucks. This helps the uterus to return to standard size more quickly.
Despite all these benefits, a mother can’t be available at all feeding times for several reasons. Hence, formula milk is an alternate option where other family members can help. It has about the same nutritional value as breast milk but provides no immunity to infants against diseases. It is expensive and requires special equipment and time-consuming preparation. There is always a risk of introducing infection; firstly, because of lack of cleanliness and hygiene during practice, and secondly, if held for some time, bacteria proliferate in formula milk. Cow or buffalo’s milk is generally not recommended for infant feeding.
Milk alone can meet the infant’s requirements until the age of 4-6 months. Afterward, however, there is a need for introducing semi-solids and later solids. This process should be gradual, starting with minimal amounts. Only one new food in a week should be submitted to the child. After giving the food, the development of allergic reactions should be observed. Signs of food allergy include rashes, diarrhea, vomiting, and abdominal cramps. Cow’s milk, egg white, fresh fruit juice, and green vegetable soup are liquid foods for the beginning.
Soft and easily digestible food should be prepared at home. Commercially available baby foods can also be used. Adding salt or sugar should be limited. Over-feeding is a bad habit that should be avoided as obese children become obese adults.
Typically at 6-9 months, finely chopped fruits and vegetables, fruit juices, and foods like toast and biscuits are good. At 9-12 months, minced meat without additional fat, egg yolk, and other chopped foods can be given. Cereals and starchy gruel prepared from malted wheat sprouted pulses and fruits and vegetables ensure a supply of the most nutrients needed for good health. After feeding the baby, teeth and gums should be cleaned with a soft, damp cloth. Teeth decay rapidly, especially if the baby sleeps with a bottle in the mouth. Hence feeding sweetened liquids by bottle should be avoided.

CHILD NUTRITION:

The children are in a rapidly growing state; hence their nutritional requirements increase with age. Their physical activity is high, as they tend to play more. Therefore, they need appreciably more energy than infants or sedentary adults. The protein needs of children are also high since they are constantly adding tissues to their bodies. The needs of both boys and girls are the same until about nine years, after which the requirements differ. The children must be provided with sufficient energy, proteins, and other nutrients to cope with their body needs.
Children are generally restless and do not have enough time for eating. Quick-eating dishes can serve their purpose. They also like variety in their diet; therefore, different foods should occasionally be introduced into the menu. The children should be encouraged to eat with the family. Their diet should include foods from each food group.
They must be provided with suitable nourishing snacks for the school. Commercially prepared foods are not that nourishing. These sometimes contain ingredients that may be toxic. It is suggested that whole wheat flour be used for chapati making and preferably blended with about 10 % gram flour (‘besan’). This will increase the protein content of the flour.

NUTRITION IN ADOLESCENCE:

 This is manifested in accelerated physical, biochemical, and emotional developments. In general, the body requirements are increased with more nourishment for boys of the same age than girls. The most significant nutrient needs for boys are between 12 to 15 years, and for girls, 10 to 13 years. Teenagers are reputed to have the worst eating habits. They may choose not to eat a meal to stay slim. They may eat fast foods generally low in essential nutrients (mineral elements, vitamins) but high in calories, saturated fats, and sodium. This can result in anemia and various health problems.