Pregnancy involves increased nutritional requirements, this means an increase in energy consumption (called increased basal metabolic rate) with the increase in nutritive elements, vitamins and minerals.
Anyway this is not excessive consumption of food, much less the increase in carbohydrate consumption although many mothers experience increased appetite or selectivity for certain foods.

The maternal weight
The ideal average weight gain in late pregnancy is (between week 38-42) 11 Kg
According to the committee on Maternal Nutrition National Research Council 1989, with a gain of 1 kg during the first trimester and 400 g per week from the second quarter.
This is due to begin forming new tissues, organs and unborn child develops.
It is important that during this period receive a correct diet in order to avoid complications and promote the normal course of your pregnancy and fetal growth.
A little weight gain, ie the bottom of 9 kg, can adversely affect pregnancy, in the sense of having a child as a result of low birth weight (less than 2.5 kg).

Studies show the existence of a relationship between fetal malnutrition and changes in weight and size of newborns who receive inadequate supply of nutrients during the gestation period, through a gap in the nutrition of the mother. It is imperative to motivate women to skinny gain weight during pregnancy than women of normal weight. This means that if you keep your weight within normal limits (9 and 12 kg) integrate the body of pregnant women with less incidence of preeclampsia, prematurity and low birth weight.

How should this weight gain?
As mentioned, the proper distribution of weight gain is 1 kg during the 1st. quarter and half (1 / 2) Kg per week steadily until the end of pregnancy.
This has a rationale, and we can explain. If we consider the 3 steps that occur during pregnancy:

* 1st. Stage: It ranges from the establishment about two weeks after conception. At this time the fertilized egg implants in the wall of the uterus and the placenta begins to develop.
* 2nd. Stage: The period of training and development of organs like heart, kidneys, lungs, liver, skeleton.
* 3rd. Stage: The future baby gains weight quickly. They develop the placenta and maternal reserves in preparation for childbirth, postpartum and milk production. At this stage it is common for mothers manifest salt and water retention.

At week 40 of gestation, we can identify these components of weight:

Child: 3.5 Kg
Size of the uterus: 900-1000 gr
Placenta and Membranes: 650-700 gr
Amniotic Fluid: 800-1000 gr
Breast Augmentation: 500 gr
Liquid Body: 1800 gr
Interstitial fluid: 1200 gr

What if there overweight before pregnancy?
First, you should not submit to strict regimes during this time. You can alter the normal development of your unborn child, can even endanger their life.
It is advised that both the overweight and obesity is treated before or after pregnancy.

What about protein?
Recall that proteins are an important nutritional principles based “plastic”, ie form new organs, tissue repair among many others. Therefore, as you can imagine your requirement is also increased in this period.
During the last 6 months of pregnancy, are deposited approximately 950 grams of protein. To offset this demand will be sufficient the addition of 10 grams of protein, preferably of animal origin in the usual daily intake of the mother.

What about calcium?
The efficiency of minerals absorption like calcium and iron increases during pregnancy, but the demands of the fetus and other tissues in need of development increases in the diet towards the second and third quarter primarily.
The extra calcium requirement during this period is about 30 grams, which coincides with the amount of calcium present in the fetus to term.
Some calcium and phosphorus are deposited at the start but most of these minerals are incorporated into the final quarter. The calcification of the bones takes place during the past two months, capturing the fetus about 300 mg / day in this period.
The first set of teeth begins to form in the eighth week of prenatal life and are well trained in late pregnancy. The same is true of the six-year molars, which are the first permanent teeth emerge, they begin to calcify before birth.
You see, it is very important for your child to have calcium. And unlike iron, calcium deposits, the mother will be used to meet the demands of the child, they represent 25% of maternal reserves.
Increasing daily calcium intake should be from the beginning of pregnancy together with the phosphorus. If you consume milk and its derivatives easily cover that adequate calcium intake.
Cow’s milk is an important food that helps not only with the contribution of calcium but protein, carbohydrate, vitamins, minerals and lipids (fats).
Approximately one liter of whole milk, fluid supplies 100% of requirement of calcium, vitamin D and almost 50% of protein intake that pregnant women need.
Vitamin D across the placenta it can reach the baby. Numerous studies concur that this vitamin deficiency in the mother may be transmitted to the child.

What about iron?
During pregnancy the mother used and will absorb between 700 and 1000 mg. Of this total, 240mg are provided by the suppression of menstrual flow and the rest should be taken with food intake. Iron requirements are markedly increased during pregnancy. This is because increasing the volume of red cells in the mother because of the iron is transferred from mother to fetus and decreasing supply.
We remind you that the red blood cells carry oxygen inter alia from the lung to the various bodies including the baby.
The usual diet is absorbed only 10% and only in circumstances where there is a real gap absorption increases to 20%.
In this connection the Committee on Maternal Nutrition of the National Research Council in 1989, recommended iron supplement in the form of ferrous salts, in this period due to regular diets rarely sufficient to cover claims.
This situation is exacerbated if the mother prior to pregnancy had anemia, menstrual losses important or if the pregnancy is multiple.

Vitamin C
This vitamin is mainly found in citrus fruits (orange, grapefruit, tangerine), enhances iron absorption. That is as important eating fruits at meals.

Foods rich in
We have seen it is very important to the ingestion of food containing plenty of iron and as there are foods that promote the absorption of this mineral (vitamin C), there are others on the contrary hinder absorption, due to the high content of phytic acid. They are usually legumes (lentils, chickpeas, beans, soy), and tannic acid in tea, among others. But do not forget that the other legumes have other desirable nutritional values. The solution is to vary the diet alternating foods that contain them and others avoid them.
The difference of folic acid is rare. The main reason is that your requirement is increased in this period. The body does not get any folate intake, for this reason is that it recommends a daily intake of 800 mcg.
With a proper diet that will be covered, and if you also careful not to use as the cooking method to use boiled or preserved, as these are easily destroyed.

Do not forget
While fresh fruits and vegetables provide few calories, its nutritional value is due to their content of vitamins and minerals.
The heat of cooking destroys many vitamins.
Sweets provide excess calories and detrimental to the teeth, which during pregnancy are very prone to decay.
Digestible fats are better for you to choose during your pregnancy. You prefer extra virgin olive oils pure and used as seasoning preparations with table margarines.
Highly salted foods such as canned meats and canned meats should be consumed with utmost restraint and if there is hypertension and / or swelling you should avoid them completely.