Pregnancy weight gain: everything you need to know

Weight gain during pregnancy is not the same for everyone. It depends on pre-pregnancy weight, height, general health, and even the number of babies expected. Official recommendations are based on body mass index (BMI) before conception. Here are the generally accepted guidelines:

• If BMI is below 18.5 (underweight), the recommended weight gain is 12 to 18 kg.
• For a BMI between 18.5 and 24.9 (healthy weight), it is 11 to 16 kg. 
• If BMI is between 25 and 29.9 (overweight), a gain of 7 to 11 kg is recommended.
• In cases of obesity (BMI over 30), the recommended weight gain is between 5 and 9 kg.

Weight gain recommendations based on BMI are useful guidelines, but they remain indicative. Every pregnant woman experiences pregnancy at her own pace, with her own specific needs. There is no universal "ideal" weight. What matters most is maintaining a varied, balanced diet with whole, unprocessed foods, and listening to your body. Rather than focusing on the number of kilos, it is more helpful to consider the quality of nutritional intake and overall wellbeing. A healthy pregnancy is not measured by the scales alone, but by how you care for yourself and your baby each day. Paying attention to your diet is above all about ensuring you get all the essential nutrients. Taking a pregnancy food supplement more may be recommended. 

During pregnancy, the body changes to accommodate and nourish the baby. Weight gain is therefore normal — indeed essential. It serves several purposes: foetal development, placental growth, increased blood volume, building up reserves for breastfeeding, and the enlargement of the uterus and breasts all require the body to adapt.

Insufficient weight gain can lead to intrauterine growth restriction or a low birth weight baby. Conversely, excessive weight gain can lead to complications such as gestational diabetes, hypertension, or a more difficult and over-medicalised birth.

Several factors come into play. The first, of course, is diet. Eating for two is not necessary: it is really about eating twice as well. A variety of foods, balanced meals rich in essential nutrients are recommended.

Physical activity also plays a role. Unless medically advised otherwise, moving every day can help limit excessive weight gain and make the body's changes easier to live with. Hormones, sleep, stress, and certain medical treatments can also have an influence.

In early pregnancy, weight gain is generally modest. Some pregnant women may even lose weight due to nausea and vomiting. From the second trimester onwards, weight gain becomes more regular, before slowing slightly towards the end of pregnancy.

On average, the following is considered typical:

• First trimester: +1 to 2 kg.
• Second trimester: +4 to 5 kg.
• Third trimester: +3 to 5 kg.

These figures are again indicative. What matters is consistency, alignment with your actual needs, and the quality of what you eat.

Excessive weight gain during pregnancy can have consequences for the health of the expectant mother. In particular, there is an increased risk of developing gestational diabetes, which often requires closer medical monitoring. It can also lead to significant fatigue, uncontrollable cravings, or complications during labour. It may also contribute to the development of gestational hypertension, with an increased risk of pre-eclampsia. Rapid or excessive weight gain can also worsen joint and lower back pain, reducing everyday comfort. Digestive and circulatory issues such as acid reflux or heavy legs may also be more pronounced. 

On an emotional level, it can also affect self-esteem and reinforce a sense of loss of control. It is therefore essential to adopt a balanced, satisfying diet that meets your needs, without falling into restriction. Listening to your hunger, moving according to your abilities, and seeking support from healthcare professionals can help you find the right balance and take care of your health.

It is also important to listen to your cravings without demonising them. Cravings are common during pregnancy and are often a sign that the body needs additional nourishment. They should neither be ignored nor be a source of guilt. The aim is to respond to them mindfully: by favouring healthy, satisfying snacks rich in good nutrients, and limiting ultra-processed foods and excess. This allows you to honour your needs while maintaining an overall balance that supports the health of the expectant mother. 

Too little weight gain during pregnancy can have an impact on the health and energy of the expectant mother. First, it can lead to increased fatigue, linked to insufficient caloric and nutritional intake to meet the heightened needs of this period. This deficit can also deplete the mother's reserves, particularly of iron, calcium and essential fatty acids, thereby increasing the risk of anaemia, muscle disorders or bone demineralisation. An insufficiently caloric or unbalanced diet can also weaken the immune system and slow postpartum recovery. Finally, a lack of energy or certain essential nutrients can contribute to mood disorders or a more intense baby blues.

To manage weight gain well during pregnancy, the goal is not to anxiously track every kilogram gained, but rather to keep a general eye on how things progress week by week.

A varied, balanced diet that listens to your hunger cues remains the foundation. It is recommended to avoid ultra-processed products, which are often high in added sugars, hidden fats and low in nutrients.

If you get cravings, it's better to have healthy, satisfying snacks to hand, such as fresh fruit, nuts, plain yoghurt or a slice of wholegrain bread with a little almond butter. Our tips: 1 pregnancy snacks Jolly Mama every day to keep cravings at bay!

Home-cooked meals, seasonal vegetables, legumes, quality proteins, and healthy fats (olive oil, avocado, oily fish) are to be prioritised.

Gentle physical activity, such as walking, prenatal yoga or swimming, helps maintain good physical and emotional balance. 2–3 sessions of physical activity per week are generally recommended. To find out more, read our article on sport and pregnancy.

Sleep and stress management also play a key role in regulating weight gain during pregnancy, as well as overall wellbeing.

Regular medical follow-up is essential. At each appointment, the healthcare professional (midwife or doctor) monitors the weight curve and can adapt their recommendations according to your needs. Personalised nutritional support from a specialist dietitian can also be invaluable for adjusting your intake, answering dietary questions and navigating this period with peace of mind.

After birth, the body does not return to its pre-pregnancy state straight away. Some of the weight (amniotic fluid, placenta, baby) is lost at delivery, but the rest takes time. Breastfeeding, if chosen, can in some cases support gradual weight loss. The most important thing is not to put pressure on yourself and to respect your own pace. To find out more, see our article on breastfeeding and weight loss. In any case, it is essential not to diet after birth, to ensure your nutritional needs are met, and if necessary to take a postnatal supplement.

Weight gain during pregnancy is a natural and necessary phenomenon. The weight gained reflects how well the pregnancy is progressing and the baby's growth. It depends on many factors: starting weight, diet, physical activity, and health status. Following general guidelines while staying attuned to your body allows you to approach pregnancy with greater peace of mind. If in doubt, do not hesitate to consult a healthcare professional, who is the only person qualified to assess the situation and offer appropriate advice and support. Taking care of yourself during pregnancy is already taking care of your baby.