How to lose weight after giving birth safely: a realistic timeline, breastfeeding and calories, and Singapore food swaps

To lose weight after giving birth safely, aim for 1 to 2kg a month, give yourself one to two years to reach your goal, and skip crash diets. That's the advice from HealthHub, written with a National Healthcare Group Polyclinics family physician. KKH's dietitian adds that you shouldn't start a weight-loss programme until your baby is about 6 months old if you're breastfeeding, because cutting food too hard can affect your milk. The plan that works is plain: regular meals with protein and vegetables, water instead of sweet drinks, walking from the early weeks, and 150 minutes of moderate exercise a week once your doctor clears you. Breastfeeding helps as well: a KKH study of 379 Singapore mothers found that those who breastfed exclusively kept the least weight on.

A realistic timeline

You lose a lot at once and the rest slowly. HealthXchange says most women lose about 5 to 6kg in the first week after the birth, as the baby, placenta and extra fluid go. HealthHub says your body's pregnancy changes settle by about 6 weeks, and that losing the rest takes time, much as growing a baby did.

Check where you are with our BMI calculator: enter your height and current weight and it shows your BMI against the Asian cut-offs used in Singapore. KKH's breastfeeding study counted a BMI of 23 or more as high. Set your goal from that number, not from old photos.

Breastfeeding and calories

Breastfeeding uses energy, and it helps. HealthHub says a balanced diet plus about 500 extra calories a day covers what you need to make milk, and that fat stored in pregnancy is used up for milk in the first 6 months. KKH's study, published in 2024, followed first-time mothers for a year:

The same study found that women with a high BMI before pregnancy who breastfed exclusively lost all their pregnancy weight and about 200g more by 12 months. Formula feeding is fine; it just means the food and exercise steps below do more of the work. Our breastfeeding diet guide covers what to eat and drink.

Food swaps that work in Singapore

HealthHub suggests keeping a food diary for a week first, so you can see where the extra calories come from. Then swap, rather than cut out meals; skipping meals makes you overeat at the next one.

Our guide to postpartum recovery foods has a 7-day meal plan built on the same idea.

Moving more, in stages

HealthHub recommends at least 150 minutes of moderate aerobic activity a week, plus muscle-strengthening and stretching, built up slowly and with your gynaecologist's go-ahead for anything moderate to vigorous. Walking with the pram, swimming once your bleeding has stopped, postnatal yoga or Pilates, and resistance training all count. Our guide to exercise after giving birth has the week-by-week timeline for a vaginal birth and a C-section.

What not to do

• Crash diets: HealthHub says very low-calorie plans that promise fast results carry health risks and can weaken your immune system.
• Slimming pills and teas: HSA has found banned ingredients such as sibutramine in slimming products sold online, and health supplements are not approved by HSA before sale.
• Dieting hard while breastfeeding: KKH's dietitian says to wait until about 6 months, because it can affect your milk.
• Comparing yourself to others: KKH's researchers note that the push in Singapore to get back to your pre-pregnancy weight quickly can add to stress and low mood.

If your weight is getting you down, or food feels out of control, talk to your doctor. Our guides to postnatal depression help and self-care for new mums list support.

Frequently asked questions

How long does it take to lose weight after giving birth?

HealthHub suggests setting realistic goals over one to two years. Most women lose 5 to 6kg in the first week, then the rest slowly; 1 to 2kg a month is a healthy pace.

Can I diet while breastfeeding?

Not a strict one. KKH's dietitian advises waiting until about 6 months before a weight-loss programme, because it may affect your milk. Eat to hunger with three meals and two or three snacks.

Does breastfeeding help you lose weight?

Yes. A KKH study found mothers who breastfed exclusively kept on about 960g at 12 months, against about 3.7kg for those who formula fed.

When can I start exercising to lose weight after birth?

Walking and pelvic floor exercises can start early. Moderate to vigorous exercise waits for your gynaecologist's go-ahead, usually at the six-week check, and HealthHub's target is 150 minutes a week.

How many calories does a breastfeeding mum need?

HealthHub says about 500 extra calories a day on top of a balanced diet, or 400 to 500 extra if you've already lost your pregnancy weight.

Are slimming teas safe after giving birth?

Avoid them. HSA has found banned drugs in some slimming products, and health supplements aren't approved before they go on sale. Ask your doctor first.