Managing Weight Gain During Pregnancy: Practical Tips from a Pregnancy Dietitian

If you’re pregnant and feeling uncertain about your body weight changes, you are not alone.

Pregnancy is a time of incredible change — physically, emotionally, and nutritionally. 

One topic that often causes confusion and stress is managing weight during pregnancy. 

It’s a delicate balance: wanting to do what’s best for your baby, staying healthy yourself, but also feeling overwhelmed by advice that ranges from outdated to outright unhelpful.

Let me reassure you — it’s completely possible to manage your weight during pregnancy in a way that feels supportive and not restrictive. Whether you’re pregnant after a miscarriage, gained weight during IVF, struggling with nausea and cravings or managing gestational diabetes.

Let’s look at what’s normal, what’s helpful to know, and how to support healthy weight gain in pregnancy.

What is “Healthy” Weight Gain in Pregnancy

Weight gain during pregnancy is both normal and necessary to support your growing baby. The weight isn't just fat – it’s the baby, placenta, extra blood, uterus, and making breastmilk for when your baby is born.

Every pregnancy is different — but the fear of “gaining too much weight” is nearly universal. And questions about how much weight is “too much”? Or “not enough” come up all the time.

Most NHS and other health guidelines offer a general framework based on your pre-pregnancy Body Mass Index (BMI). For example:

• If you were in a healthy BMI range before your pregnancy, you might expect to gain around 11.5-16 kg during pregnancy.

• If already overweight or you were above that range (i.e. BMI>30), recommendations change to about 5-9kg during the pregnancy.

• If you are pregnant with twins, or you have diabetes or prior weight loss surgery, it may mean different weight gain recommendations and additional nutritional considerations. 

But these weight targets are guides, not hard rules.  What matters most is how you're nourishing your body. (Not obsessing over how much weight you gain each week). 

The table below shows what weight gain to expect by each trimester and possible reasons for fast, excessive or unusual weight gain.

Trimester	Weight Gain by Pregnancy Trimester
First	- Little to no gain (1–2kg) or even slight loss due to nausea. - Bloating is common and can feel like weight gain. - Some women gain early, some later—some feel hungrier in the first trimester, others not until the third trimester.
Second	- Baby grows rapidly. - Steady weight gain begins (~0.5kg/week). - in this trimester you gain the most weight
Third	- Growth continues. - Some plateau in weight gain due to reduced appetite, heartburn or baby pressing on stomach.
Possible Reasons	For Fast, Excessive Or Unusual Weight Gain
Medical Causes	Sudden weight gain might signal fluid retention, gestational diabetes, increase in blood pressure or preeclampsia and the need of a C-section — check in with the midwife.
Lifestyle Factors	Excessive weight gain can increase the risk of retaining this weight after birth. Research shows that more than 50% of overweight women will gain 10kg or more than recommended by week 20 of their pregnancy. Too little weight gain might cause an earlier birth (before 37 weeks) or your baby being born small (less than 2.5kg).  Emotional eating, food aversions, low activity, cravings, or portion sizes can all contribute.
Natural Variation	Weight gain isn’t always linear. Some weeks are faster than others. Fast or early weight gain doesn’t mean you’ve “failed” — your body is adapting.  Unintentional weight loss of more than 6kg, at any time during your pregnancy (first, second or third trimester) or because you have had an extended period of pregnancy sickness needs reviewing by your doctor, midwife and/ or dietitian If you’re worried about your weight gain, talk to your dietitian or midwife.

As a UK registered pregnancy dietitian, I work with women to personalise their target weight based on their needs and how their pregnancy is progressing. 

The support you’ll get might look like how to:

✅ Adapt your nutrition to trimester -specific needs (because a lot can change in 9 months). There are certain nutrients that are important for the healthy growth and development of your baby including folic acid, calcium, iodine and omega-3.

✅ Focus on eating patterns when your physical activity is limited (e.g. due to pelvic girdle pain, exhaustion, or nausea).

✅ Eat a healthy diet to support iron absorption, digestion and regular bowel movement or blood sugar balance. 

✅ Respond to your own hunger rhythms. Let's face it, some days you’ll need more, some days less. You don’t need to follow diet rules BUT learning to trust your body is key.

Truth is the number on the scale is only one small part of the picture. 

Together we will focus on how you feel… your energy, digestion, sleep and stress, because these are all signs of good nutrition and balance. Preparing your body this way can support you to avoid gaining excess weight and lose that extra weight after the delivery of your baby. 

Client Story: “Can I lose weight safely while I'm pregnant?”

Sarah (name changed) came to me in her first trimester. She wanted to avoid the 20kg+ weight gain she had during her first pregnancy which led to reduced mobility and a C-section.   

She was already feeling exhausted and craving sugar, and panicking about how to control her weight while pregnant. After we reviewed her food intake and lifestyle, I spotted what was really going on:

• She was skipping breakfast, setting herself up for blood sugar crashes by 11am.

• She was constantly grazing in the afternoon to fight fatigue (fatigue is completely normal, by the way).

Together, we made small but targeted changes: 

✅Adding high fibre and slow releasing carbs to breakfast like oats or sourdough bread paired with a nut butter

✅ Introducing a structured afternoon snack to manage hunger pangs 

✅Began journaling her energy patterns and hunger cues

Her weight gain was steady throughout the pregnancy but more importantly she enjoyed the pregnancy up until the very end and had a natural birth.  With clarity and confidence she learned to stop eating when she felt full, without any guilt or restriction.

She felt better, and managed nausea and cravings better than during her first pregnancy and was able to participate in prenatal activity classes. 

Common Pregnancy Weight Challenges I See — and How We Tackle Them Together

You're not alone if you've experienced any of these:

#1. Cravings spiralling out of control?

You’ll satisfy your cravings without letting them take over. It’s not about saying no — it’s about creating structure to your day and balanced meals that reduce the urge to snack endlessly.

#2. Constant snacking due to tiredness or nausea?

This is very common in the first trimester. You’ll plan ‘mini-meals’ that pair carbs with protein and fibre so you can stay energised without feeling stuffed.

#3. Fear of “messing up” your pregnancy by eating wrong?

So many women come to me with years of dieting behind them. You’ll rebuild trust in your body and shift from guilt to guidance and confidence you’re doing the best for you and your baby.

#4. Already at a higher BMI and feeling judged?

You deserve respectful support — no matter the starting weight. We focus on what’s within your control and how to support a healthy pregnancy together. You don't need to “stop” or slow down the weight gain in pregnancy. It's about finding a steady pace with regular balanced meals that support digestion (because constipation can make women feel heavier) and gentle movement. 

#5. Busy at work and no time to cook?

We build a meal plan framework that gives you easy swaps for when you're tired, on-the-go, or can’t face cooking. This is tailored for vegans and vegetarians or even just veg-avoiders and fussy eaters.

Why Generic Pregnancy Advice Falls Short — and What You Really Need

General advice from social media and forums can only take you so far. They don’t know your history, your body, your cravings or your real-life routines.

That’s where tailored support and guidance makes the difference. 

Pregnancy isn’t just about managing weight — it’s about building a lifestyle that will support you into motherhood and early postpartum period.

That’s why my healthy weight gain for pregnancy programme includes:

✅ Pregnancy nutrition support across all trimesters 

✅ Guidance for meal planning and mindful eating 

✅ Tools to prevent rebound weight gain postpartum 

✅ Accountability and support — especially when motivation drops or symptoms get worse

You deserve that level of care too.

Final Thoughts: You Don’t Need to Be Perfect — You Need Professional Support During Pregnancy

Pregnancy is not the time to go on a diet — it’s the time to be intentional, nourished, and supported. Gaining weight doesn’t mean losing control—especially when done mindfully and with intention.

You don’t need to count calories, restrict, or feel guilty — you need clarity, structure, and support.

Book Your Free Discovery Call Today

If you're unsure how to navigate food and weight during pregnancy and want an expert by your side — let’s chat. You’ll get personalised support and a tailored nutrition plan to feel confident and your best in pregnancy.

Discovery Call

Book Now

Dr Katie Psarou

Dr Katie Psarou is a UK registered fertility and pregnancy dietitian who specialises in weight management. She supports you to reach a healthier weight, speed up your fertility journey and achieve a healthier pregnancy with personalised nutrition plans.