Prenatal Weight Gain and Metabolism

Pregnancy is a time of emotional and physical transformation and challenges. While for most women it’s a time joy, hope, and excitement, it can also mean stress, uncertainty, and worry, especially about weight gain.

Questions such as, “Will I gain too much weight?” or “Will I be able to lose the baby weight?” concern most pregnant woman. After all, weight gain is a natural and healthy part of pregnancy. Unfortunately, over-gaining is becoming increasingly commonplace, and may have long-term health implications for both mother and child. Complicating matters, over two thirds of women in the US now enter their childbearing years in the overweight or obese category. The myth that women should “eat for two” lingers on, despite clear evidence to the contrary.

Many of us are hyper-conscious of our body weight before we become pregnant, and have strong emotions regarding our bodies (especially those of us who have struggled with weight management). With every prenatal visit, we are weighed, measured, and evaluated against statistical norms. While necessary to assure prenatal health, these tests may also reinforce our fears about weight gain.

Fortunately, the amount of weight that you gain during pregnancy is not simply a matter of genetics or luck. You can easily gain the perfect amount of pregnancy pounds by eating a high quality diet that is in balance with your specific metabolism. Think Goldilocks: not too little, not too much, but just right!

Healthy Prenatal Weight Gain: Where Does it All Go?

Typical Healthy Weight Gain During Pregnancy:

Baby6 - 8 lbs
Placenta2 - 3 lbs
Amniotic Fluid2 - 3 lbs
Uterus3 - 4 lbs
Breast Tissue2 - 3 lbs
Blood Volume3 - 4 lbs
Other Fluids3 - 5 lbs
Fat Storage4 – 5 lbs
Total25 - 35lbs      

Recommended Weight Gain by Trimester

Weight gain recommendations are based on Body Mass Index, or BMI.

Underweight or BMI< 18.5
1st Trimester:3 – 6 lbs
2nd Trimester:1 lb. per week
3rd Trimester:1 lb. per week
Total Weight Gain:28 – 40 lbs
Normal Weight or BMI of18.6– 24.9
1st Trimester:1 – 6 lbs
2nd Trimester:1 lb. per week
3rd Trimester:1 lb. per week
Total Weight Gain:25 – 35 lbs
Overweight or BMI of25 – 29.9
1st Trimester:0 – 6.6 lbs
2nd Trimester:.6 lb. per week
3rd Trimester:.6 lb. per week
Total Weight Gain:15 – 25 lbs
Obese or BMI of30 or more
1st Trimester:0 – 4.4 lbs
2nd Trimester:.5 lbs per week
3rd Trimester:.5 lbs per week
Total Weight Gain:11 – 20 lbs

Succeed with BeFit-Mom’s Perfect Pregnancy and Postpartum Pounds App

BeFit-Mom’s Perfect Pregnancy and Postpartum Pounds App determines your BMI (body mass index), your specific metabolic rate, and the ideal number of calories that you need throughout all three trimesters, identifies your range of ideal weight gain, and tracks your rate of gain. Knowledge about these key health prenatal health parameters puts you in control, and gives you the power to have a healthy pregnancy and baby.

Risks of Too Much Weight-Gain During Pregnancy

With obesity rates continuing to rise, two thirds of women in the US now enter their childbearing years either overweight or obese. This has lead to an alarming increase in the occurrence of gestational diabetes and other pregnancy complications that threaten the health of both the mother and her unborn child.

Because women who over-gain during pregnancy are less likely to return to their pre-pregnancy weight, excessive weight gain during pregnancy has now become a significant factor in rising obesity rates for women.  Associated health problems, during and after pregnancy, are on the rise proportionally.

Risks For Mom:

  • Increased risk of Gestational Diabetes  
  • Increased risk of overly large baby
  • Increased risk of high blood pressure
  • Increased rates of C-section
  • Increased risk of labor complications and interventions
  • Difficulty hearing fetal heart rate and measurement of uterine growth
  • Less likely to return to pre-pregnancy or healthy weight

Risks For Baby:

  • Born with excessive body fat
  • Increased risk of childhood obesity
  • Increased risk of developing Type 2 Diabetes
  • Possible altered glucose regulation
  • Possible increased risk of other health problems as an adult 

Benefits of Healthy Weight Gain During Pregnancy 

Gaining the right amount of weight for your pregnancy provides important health benefits to you and your developing baby.

Benefits For Mom:

  • Reduces risk of premature birth
  • Reduces risk of pregnancy complications
  • Reduces incidence of cesarean delivery
  • Reduces risk of developing health complications after childbirth
  • Faster return to pre-pregnancy weight

Benefits For Baby:

  • Ensures that baby reaches ideal birth weight
  • Reduces risk of birth defects
  • Enhances brain development
  • Increases likelihood of better health through childhood and adulthood

Fears about Pregnancy’s Impact on the Body

For women who have long struggled with weight control, the additional weight gain of pregnancy can further challenge her sense of personal power, control, and self-image.
Anxiety, depression, stress over body image, or a perceived lack of control over weight gain may trigger emotional eating, poor nutritional choices, or binge eating.

On the other side of the spectrum, very lean or athletic women may worry that pregnancy will “ruin” their bodies, that they’ll lose fitness, or that pregnancy represents the “beginning of the end” of their youth, vitality, or physical prowess.

Beneath all our weight-gain anxiety lies the core issue, the nagging fear—conscious or not—that our bodies, and therefore ourselves, will be less attractive and desirable after pregnancy.

By using the Perfect Pregnancy and Postpartum Pounds App, you will discover your ideal weight gain parameters, plus the number of calories that your individual body needs to fuel a healthy pregnancy. The Perfect Pregnancy Pounds App puts you in control of your health and your pregnancy.

Banish Fears with Practical Facts

Maternal health and fetal health are one in the same. Your developing baby’s future health depends directly on what you eat and how well you take care of your body. Therefore, a key aspect to being a great mom, even before your baby is born, is to make nutrition and physical activity top priorities during and after your pregnancy.

As we have seen, the amount of weight a woman gains during pregnancy, and how fast she rebounds afterwards, is not controlled by genetics or luck. Prenatal weight gain is primarily a direct consequence of mom’s nutrition and fitness habits during pregnancy.

Unfortunately, inaccurate or misleading information about prenatal weight gain, nutrition, and exercise during pregnancy persists, leaving women uncertain about what actions they should take to promote optimal health during and after their pregnancies.

Balance Quality with Quantity

To optimize nutrition during pregnancy women should eat the highest quality diet available to them. Eating a high-quality diet while actively avoiding environmental toxins—particularly cigarette smoke and alcohol—is of primary importance and nurtures both you and your baby.

Optimal prenatal nutrition balances quality with quantity. 

Disregard Messages of a “Super-Size-Me” Society

Pregnancy increases your body’s need for protein, calcium, iron, other minerals and vitamins, and water. Pregnant and postpartum women need to consume generous amounts of nutrient-rich fruits and vegetables, whole-grain breads and cereals; calcium-rich dairy products; lean protein-rich foods such as meats, fish, and legumes and “good” fats that are rich in Omega-3s such as olives, olive oil, seeds and nuts, and avocado. (For more specifics on what to eat during pregnancy, consult your doctor, or a certified nutritionist.) A daily prenatal vitamin, to fill in any nutritional gaps is recommended, and should be started before conception, if possible.

Many women are uncertain about the number of calories that they should consume in order to optimize prenatal nutrition and health. By using the Perfect Pregnancy Pounds App, you can accurately estimate your specific calorie needs, and prevent unwanted pregnancy pounds, enhance self-image, and have a healthy pregnancy.

To achieve these prenatal health goals, you need to eat a high-quality diet that balances your individual metabolism as it adjusts during the three trimesters.

Metabolism Increases to Support Your Growing Baby

Pregnancy is work, and raises metabolic rate. Your body is not only growing a baby, but also building the infrastructure—increased blood volume, placenta, and breast tissue development for milk production—that will support your baby before and after birth.

The First Trimester

These metabolic demands are not significant during the first trimester, and women who start pregnancy with a BMI above 18.5 do not need increase their daily caloric intake during this period. Only women who start in the underweight category, a BMI less than 18.5, should increase their overall calorie intake and increase protein consumption during the first trimester.

The first trimester represents about 93 days, and if you start eating more “for the baby” during this time, you’ll unintentionally start gaining at too fast a pace. As shown in the chart at the top of this chapter, ideal first trimester weight gain is minimal for most women. Overeating just 300 calories per day in your first trimester can pack on an unwanted and unnecessary eight pounds of fat, but more concerning, may establish the habit of over-consumption for the rest of your pregnancy.

The Second and Third Trimesters

During the second and third trimesters, basal metabolism increases about 300 additional calories per day over your pre-pregnant basal metabolism. To meet this increased demand, women with BMIs of between 18.5 and 24.9 should increase their calorie consumption by about 300 calories per day. In practice, this represents one additional healthy snack during the day.

To prevent excessive fat storage, women who start pregnancy with a BMI of over 25 should not increase their calorie consumption by the full 300 per day in the 2nd and 3rd trimesters. For overweight and obese women, the decision to not fully increase their calorie consumption in response to the rise in metabolism is safe.

During pregnancy our body’s normal glycogen-based energy system fuels the developing fetus and placenta. Mom’s body switches over to using primarily stored fat for energy. Because overweight and obese women have an over-abundance of stored fat, it is safe for these women to modestly limit calorie intake, and therefore prevent or limit additional fat storage, without harming fetal growth and development.

The Perfect Pregnancy Pounds App will you determine the ideal number of calories for your body throughout all three trimesters, relative to your BMI and rate of weight gain, and assist all moms-to-be in having a healthy pregnancy without excessive weight gain.

Be Wary of Misleading, One-Size-Fits All Guidelines

Too often, nutritional guides for pregnancy are “one-size-fits-all” and advise pregnant women to consume a minimum number of calories (usually in the range of 2,000) every day during pregnancy. But this common, too general approach does not take into account height, pre-pregnancy weight, age, basal metabolism, lean mass ratio, body type, or activity level. If you’re lucky enough to be of average height and enter pregnancy at an ideal weight, then this advisement will probably work for you. But if you’re not “average” in all of the above factors, this advisement will not guarantee that you gain the ideal amount of weight, or optimize your prenatal health.

Given that two thirds of women of women in he US now enter their childbearing years either overweight or obese, this one-size-fits-all advisement no longer makes sense and can lead to long-term negative health impacts for both mom and baby.

Women who consume an average of just 300 calories per day over their actual metabolic rate over the course of their pregnancy will pack on an additional 24 pounds of unwanted and unnecessary fat. Whether intentional, or unintentional, even a relatively small over consumption of calories on a regular basis during pregnancy can have undesirable health impacts. And of course, losing extra pregnancy pounds after your baby is born is much more difficult, as it requires a consistent caloric deficit over many weeks, compared to eating caloric balance throughout your pregnancy.

Put Weight Gain in the Proper Perspective

A small amount of additional fat-storage during pregnancy is healthy, and a basic component of female physiology. It’s a critical aspect of our success as a species as it ensures that we have enough energy stores to fully nurture our newborns, even in the face natural disasters. In fact, fat storage during pregnancy is a phenomenon found universally throughout the animal world.

As you can see from the chart at the top of this page, with an average, healthy weight-gain of 25 to 35 pounds during pregnancy, only 3 to 6 pounds comes from additional fat stores. Looked at from this perspective, stocking the pantry with 3 to 6 pounds is fairly modest, and certainly not worth all the worry and stress that we commonly subject ourselves to during pregnancy.

Store Less Fat in the Last Trimester and Bounce Back Fast!

If you eat well, and in the proper amount, most of these additional fat stores are laid down in the third trimester, to ensure adequate energy reserves for breastfeeding. Studies consistently show that women who remain physically active during the last trimester (activities like fitness-walking on most days of the week) store less additional fat and lose weight more rapidly after childbirth.

Counter Negative Thoughts with Reassuring Facts

Far too many women equate prenatal weight gain with “getting fat,” which is not accurate. But as we look into the mirror at our growing bellies, many of us forget facts. Our emotions are given voice, and we say things like “I look so fat,” or “I feel so fat.” When we step on the scale and read the rising numbers, again we incorrectly identify ourselves as “getting fat.”

During pregnancy, weight gain is not synonymous with fat gain. These types of thoughts are factually inaccurate and if left unchallenged, erode self-esteem and create unnecessary psychological stress.

Monitor your internal dialog. When you hear self-deprecating thoughts, push a mental delete button, and throw that information away. Then replace faulty information with nurturing, healthy, reassuring facts. Recognize this pattern for what it is—a distortion of your body image generated by stress and uncertainty, something every woman, pregnant or not, experiences. As you develop positive-thinking patterns, you will be on the path to better health, enhanced self-image, self-acceptance, and happiness.



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