Under-fueling is incredibly common for new mums—but running on empty has real consequences for your recovery and energy levels.
The Reality of Eating as a New Mum
Let's be honest. The first weeks and months after having a baby look nothing like the serene postpartum scenes in magazines. Meals are eaten quickly, usually one-handed, often while sleep-deprived, breastfeeding and wrangling older kids. Sound familiar? You're not imagining it. This is the real, messy, completely normal reality of early motherhood.
What many women don't realise is that under-fueling after childbirth is extremely common. Between the chaos of a newborn's schedule and the physical demands on your body, it's all too easy to run on empty without even noticing. And here's the thing: when your tank stays low, it shows up in ways that are easy to dismiss as just "normal tiredness."
When Exhaustion Might Mean More Than Just Sleep Deprivation
Exhaustion, mood swings and brain fog are often signs that your body is running low on essential nutrients. New mums tend to soldier on, attributing everything to broken sleep. But nutrition matters enormously in this window. Your body has been through something enormous. It lost blood during delivery, and it needs actual fuel to repair and recover.
If you're breastfeeding, this picture gets more complex. Nursing mothers need roughly 300–500 additional calories per day to support milk production. That's not a suggestion. It's a physiological reality. Without it, your body will pull from its own reserves, which are already depleted.
Why Protein Deserves More Attention
Protein is essential for all new mothers to repair tissue and restore blood lost during delivery. Think of it as building material for your recovery. Yet protein often takes a back seat when meals become grab-and-go affairs. If you're skipping protein because you're too tired to cook, or relying on quick carbohydrates to get through the exhaustion, you're not giving your body what it actually needs right now.
Small additions help. Adding an extra serve of Greek yoghurt, a handful of nuts, or some cheese to your quick meals can make a real difference without requiring elaborate cooking. Your body is doing heavy lifting. It deserves quality inputs.
The Hidden Micronutrient Gap
Here's something worth understanding: breastfeeding increases certain micronutrient needs by up to 50%, and prenatal vitamins don't always meet the Recommended Daily Allowance for every key nutrient. If you've been leaning on your prenatal supplement thinking it covers everything, it might not be doing the job alone.
Your micronutrient demands during lactation are significantly higher than during pregnancy for several nutrients. Prenatal formulas were designed before you started breastfeeding. The math doesn't always add up.
Up to 75% of postpartum women are deficient in vitamin D, according to research published in Frontiers in Nutrition 2026. This matters because vitamin D affects immunity and bone strength. Some research also suggests it plays a role in mood, though the mechanisms are still being studied. Getting your levels checked is something to discuss with your doctor.
Anemia is extremely common after childbirth, affecting somewhere between 50–80% of new mothers. Iron underpins energy production at a cellular level. Low iron can leave you feeling flat, breathless, and like your brain simply won't engage. Post-birth blood loss makes this a realistic risk for many women.
Hydration Is Not Optional
All postpartum mothers should aim for at least 2–3 litres of water daily. If you're breastfeeding, water is literally the main ingredient in your milk. Dehydration creeps up quickly when you're focused on the baby and forgetting to drink. Keep a bottle nearby and sip throughout the day, not just at mealtimes.
Caffeine can actually make hydration harder, so water needs to be your primary fluid. If plain water feels boring, adding a splash of fruit or some cucumber can make it more appealing without adding significant calories.
What You Can Do Now
Practical moves work better than perfect plans when you're running on limited sleep. Stock your fridge with ready-to-eat protein options: boiled eggs, cheese, hummus, roasted nuts. Batch-cook something simple over the weekend and portion it out. Smoothies with protein powder and full-fat milk can bridge the gap when you genuinely cannot sit down for a proper meal.
Ask your doctor about testing your iron and vitamin D levels. This isn't overthinking. It's useful information. If your levels are low, targeted supplementation is far more effective than guessing. Your GP or women's health physio can help you understand what your specific situation requires.
Getting nutrition right during the postpartum period isn't about perfection. It's about building in small, realistic habits that slowly stack up. Your body has done something extraordinary. Fueling it properly isn't selfish. It's sensible.
Educational content only. Not a substitute for medical advice. Talk to your doctor about your specific situation.
References
- Tariku MK, Gedefaw Abateh M, Adane A, et al. Undernutrition among exclusive breastfeeding mothers and its associated factors in Southwest Ethiopia: A community-based study. PLOS ONE. 2024.
- Frontiers in Nutrition. Nutritional status of iron and vitamin D in postpartum women in northern Taiwan. Front Nutr. 2026.
- Martins MC, Silva AS, Soares NRM, et al. Vitamin D postpartum concentrations: Relationship with nutritional condition and morbidities during pregnancy. J Pregnancy. 2018.
- Milman N. Postpartum anemia I: definition, prevalence, causes, and consequences. Ann Hematol. 2011;90:1247–1253.
- Daru J, Zamora J, Fernández-Félix BM, et al. Current concepts in postpartum anemia management. Curr Opin Anesthesiol. 2024.
- Dusdieker LB, Hemingway DL, Stumbo PJ. Impact of breastfeeding on maternal nutritional status. In: Advances in Experimental Medicine and Biology. Springer; 2004.
Common Questions
Why am I so exhausted as a new mum, and could it be more than just broken sleep?
Feeling completely drained is definitely common in the early postpartum weeks, but chronic exhaustion may signal that your body isn't getting the fuel it needs to recover from childbirth. When you're under-fuelling while managing the physical demands of caring for a newborn, your nutrient stores can become depleted, affecting your energy, mood and mental clarity. If you're breastfeeding, your body is working hard to produce milk on top of recovering from delivery. It's worth considering whether nutrition is playing a role in your tiredness, especially if rest alone isn't helping. Talk to your GP if exhaustion feels persistent or overwhelming.
How many extra calories do I need while breastfeeding?
Breastfeeding generally requires approximately 300–500 additional calories per day to support milk production, though this varies depending on your activity levels and milk supply. Beyond calories, your body also needs specific nutrients—protein, iron, calcium, vitamin D and omega-3 fatty acids—to maintain your own health while supporting your baby. Some women try to eat less while breastfeeding to lose weight quickly, but this can compromise your milk supply and leave you feeling depleted. If you're unsure about your energy needs, chat with your GP or an Accredited Practising Dietitian.
What nutrients do I actually need more of after having a baby?
Postpartum and breastfeeding increase your needs for several key nutrients, including protein for tissue repair and recovery from delivery, iron to replenish blood loss, calcium and vitamin D for bone health, iodine for thyroid function and brain development in your baby, and omega-3 fatty acids (particularly DHA) which support both of you. Research suggests up to 75% of postpartum women may be deficient in vitamin D, which is important for immunity, bone strength and potentially mood. Focusing on nutrient-dense whole foods and understanding where your diet might have gaps can make a meaningful difference to how you feel.
Can I just keep taking my prenatal vitamin while breastfeeding?
Prenatal vitamins were designed to meet the nutritional needs of pregnancy, not necessarily lactation, and your requirements shift after birth. While continuing your prenatal supplement provides a helpful foundation, it may not fully cover your increased needs for certain nutrients during breastfeeding. Your micronutrient demands during this period are significantly higher for several key nutrients. It's worth reviewing your supplement with your GP or asking about having your vitamin D levels checked, especially if you're spending a lot of time indoors with a newborn.
How can I prioritise protein when I'm too exhausted to cook?
You don't need elaborate meals to increase your protein intake—small, practical additions make a real difference. Keeping grab-and-go options like Greek yoghurt, hard-boiled eggs, a handful of nuts, cheese, or hummus nearby means you can add protein without much effort. Batch-cooking basics like shredded chicken or having tinned fish on hand lets you throw together a quick, protein-rich meal. The key is reducing the friction between hunger and eating well. And remember, this season of motherhood is demanding—your body needs quality inputs to support both your recovery and your ability to care for your baby.
Jess Mizzi, CPT
Certified Personal Trainer and founder of FitForHer. Specialises in women's life-stage specific fitness — postnatal recovery, perimenopause, and menopause. About Jess →
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making changes to your exercise or nutrition programme.