Q & A: What is the right amount of weight to gain during pregnancy?

What is the right amount of weight to gain during pregnancy?

The trick is to gain enough weight to ensure the optimum weight, health and nutrition for the baby, while not putting on so much weight that you have an uncomfortable pregnancy and/or complications, and are not left with masses of fat to lose after the birth.

The recommendations for weight gain are usually based on those produced by the USA National Academy of Sciences Food and Nutrition Board in the l990s. These recommend weight gain of anything from 7 - 18kg, depending upon your pre-pregnant weight.

Based on these, the ideal average weight gain for the ideal female Body Mass Index of 22.5 is 13.75kg or 30lbs. This is higher than the ideal weight gain recommended in the l970's and 1980's of 20 - 28lbs, which was based on women's average weights in the 1950s - which were, of course, considerably less than they are now.

The weight of the foetus, placenta and other essentials is usually about 20 - 22lbs; the rest of the gain is maternal fat. At an average weight gain of 13.75kg (30lbs), up to 10lbs would be fat. Research shows that although high weight gain in pregnancy may be associated with more complications, prolonged labour, and retained maternal weight after the birth, the extra weight appears not to adversely affect the baby - rather, it may be born with a higher than average birthweight which may not be a disadvantage.

On average, most of the weight gain will take place from the fourth to the eight months of pregnancy. A weight gain of 3lbs or so is adequate in the first three months; after that about 1lb a week until week 36 is about right.



Is plenty of exercise the best way to keep my weight down during pregnancy?

You don't really want to keep your weight down, as such, during pregnancy - you want to gain weight (see previous question). But if you mean that you see exercise as a way to ensure that you don't put on too much weight during pregnancy, then you are partly right. Regular exercise, suitable for pregnancy, can help to keep you fit and a reasonable weight. However it depends upon your definition of 'plenty' of exercise.

A lot of the more vigorous types of exercise - such as jogging, cycling, rowing or much gym work - become increasingly difficult to perform when you are in the later stages of pregnancy and I wouldn't advice these as there is some research that vigorous exercise in the ast few months can adversely affect the baby. You will also tend to become easily tired in the last few weeks when it may be preferable to cut exercise down to small, easy sessions rather than long, calorie-burning sessions. Also many women find that they are very tired in the first 2 - 3 months and prefer sleep and rest to taking a lot of exercise.

If you have been a regular vigorous exerciser you will probably find that you can do a lot more than someone who hasn't been used to these forms of activity. But if you are someone who has done only mild or moderate exercise, you shouldn't suddenly take up a vigorous sport or exercise when you become pregnant. Walking and swimming are probably the two most ideal forms of aerobic (calorie-burning) exercise for pregnancy.


A pregnant women is - or should be - a perfectly healthy woman, and there is no reason in that case why you shouldn't exercise whenever you feel you want to, but you should take advice from your own pre-natal clinic on the best forms of exercise for your own state of health and pregnancy.

NOTE: Women with a history of miscarriage and/or any problems in early pregnancy should seek professional advice before doing any exercise.



When my baby is born what is the best way to get my figure back to normal?

Breastfeeding, healthy diet and progressive exercise.

Because breastfeeding uses up around 500 calories a day it is an ideal way to create a small calorie deficit so that you gradually lose any surplus pounds you gained during the pregnancy. Breastfeeding also contracts the uterus quickly so that it shrinks back to normal size, has many health benefits for the baby, and is convenient, so I strongly recommend breastfeeding rather than bottle feeding.

You do need extra nutrients while breastfeeding - and so it is important that your diet is healthy, including some extra calcium-rich foods such as milk (skimmed is fine), yogurt and cheese. Whether or not you are breastfeeding, you don't need high-fat high-sugar and/or high-salt snacks such as cakes, biscuits, crisps, creamy desserts, and so on, so if you were eating a few too many items like that in your pregnancy, now is the time to make a big effort and cut right back on them.

You also need to begin to exercise your body back into shape, but don't start anything but very basic gentle exercise until after your 6-week check up, and do nothing at all until then if you have had a Casarian and get your doctor's all-clear. Even then, many women do feel very tired and some feel stressed post-natally for many months, and you shouldn't feel guilty if you don't exercise every spare minute of the day. Just do what you can to make yourself look and feel better - anything is better than nothing, and making a little time for yourself each day is an important part of getting your 'self' back together in the months after your baby is born.

The post-natal 'T' factor
A gene - called 825T - has been discovered which explains why some women get their figures back quickly after the birth and others don't however hard they try. Reported in The Lancet in 2000, the gene causes women who have it to remain overweight in the year after giving birth, while women without 825T regain their figures without trouble and seemingly, without doing anything special.

About a third of white western women may be carriers of 825T - but even if you do have the 'fat gene', regular exercise of at least two hours a week can overcome the disadvantage, the researchers found.



Is weight gain inevitable for a woman during and after the menopause?

Despite the fact that so many women say that they gain weight during the menopausal years, several recent studies - particularly two important analyses conducted in the USA and reported in the International Journal of Obesity in mid-2001 - have come to the conclusion that neither the perimenopause (the years immediately before the menses cease), menopause, nor HRT, are the cause of women's weight gain at that time.

The conclusions drawn, by studying hundred of women from 17 years before, to 22 years after, the menopause, were that from about age 35 - age 65, women, on average, gain total body weight gradually and steadily and that neither loss of ovarian hormones nor their replacement with HRT makes a detectable change in this pattern.

The World Health Organisation broadly seems to agree with this - in its major report on obesity in 2001 it said that most of the weight gain associated with menopause has been attributed to reduced activity. The American studies came to the conclusion that although many women gain several pounds during the menopause transition this is simply part of the 'bigger picture' of a gain of around 0.43% per year during mid life. For a woman weighing 10 stone this would represent under 1lb a year.

In fact in one of the trials, about three years after onset of the menopause there was an average 3% weight loss in the women studied - a blip which the researchers couldn't explain.
It does therefore seem that you don't have to gain weight over the menopause, but that most women do slowly gain weight throughout middle age, due to the slowing down of the metabolic rate and a typical lack of physical activity.

So if weight gain in mid life is not associated with menopause - is it still inevitable during the 'mid' decades of life? Even in fit people, a small change in body shape in midlife does seem to happen - particularly thickening of the waist - but large weight gains can be kept at bay with a sensible diet, with resistance exercise to maintain muscle mass (or blunt muscle loss) and aerobic exercise to burn calories.

As one of the US studies says, a powerful predictor of elevated BMI (increased weight) in those studied was physical inactivity - suggesting that the most useful intervention for preventing weight gain in mid-life women is increasing physical activity levels.



So why, then, do so many women say they have piled on weight over the menopause?

Experts say that the lowered levels of oestrogen in the body tend to redistribute body fat, increasing fat deposits around the waist while legs and arms may get thinner. Therefore dress size will increase, and women taking synthetic progesterone as part of HRT may suffer fluid retention, compounding the effect. Other women become very tired during the menopausal years or have other adverse symptoms, which undoubtedly makes it harder to motivate themselves to exercise, and comfort eating may also be a small factor for some.

Although there seems to be no evidence to prove it, I don't doubt that some women do experience weight gain over the menopausal period, over and above the 'normal' slow increase of the mid life years, even if they make no changes in their lifestyle, exercise or eating patterns. Plumper women tend to produce more natural oestrogen after the menopause and some experts believe this may be a factor in encouraging weight gain. After all, the figures quoted in the research papers work on averages, not individuals. Perhaps in years to come a 'menopausal weight gene' will be found in some women, just as the post-natal 'fat' gene has been found in some mothers (see earlier question).