If you’re expecting twins and searching for solid, research-backed nutrition advice, you’ve probably run into a frustrating reality: the information is vague, outdated, and often just… missing. 

Why is it so hard to find reliable guidance on twin pregnancy nutrition?

Twin pregnancies come with higher nutritional demands, greater risks, and unique challenges — so why isn’t there more research or guidance available? 

Let’s break down the key reasons why twin pregnancy nutrition guidelines are so limited — and, more importantly, where you can turn for guidance to ensure you’re getting the nutrients that you and your babies need.

Twin Pregnancy Nutrition: Why the Guidelines are Limited and Vague

There’s a Major Lack of Research on Twin Pregnancy Nutrition

One of the biggest reasons twin pregnancy nutrition is poorly understood is that there’s simply not enough research. 

The vast majority of pregnancy nutrition studies focus on singleton pregnancies, meaning women expecting twins are left without evidence-based recommendations that truly fit their needs.

The following issues are some of the reasons why there are a limited number of studies on twin pregnancy nutrition:

• Small Sample Sizes: Twin pregnancies make up only about 3% of all pregnancies in the U.S., which means most studies lack a large enough group of twin pregnancies to draw meaningful conclusions. 
• Funding Issues: Research is expensive, and twin pregnancies are often seen as too niche to justify large-scale studies. This leaves healthcare providers relying on general pregnancy nutrition guidelines — guidelines that don’t account for the higher nutrient needs of twin pregnancies.
• Ethical Considerations: Studying twin pregnancies can be tricky. Researchers can’t ethically restrict or manipulate diet during pregnancy the way they might in other types of studies (without risk of harming the babies), making it harder to get high quality data.

Rather than having tailored recommendations, twin pregnancy nutrition is often treated as if it’s just a scaled-up version of singleton pregnancy. But this approach ignores key differences in nutrient needs, metabolism, and fetal development. 

A significant finding from my review of the research on twin pregnancy nutrition is the gap between existing dietary guidelines and the latest evidence. Many guidelines are based on data from singleton pregnancies and do not fully account for the unique needs of twin pregnancies. Ultimately, we need more research specifically focused on twin pregnancies to develop evidence-based nutritional guidelines that can better support the health of both mothers and babies in multiple gestations.

Most Twin Nutrition Recommendations Are Based on Older Studies or Observational Research

When twin pregnancy nutrition is addressed in research, much of the guidance comes from studies that are decades old. For example, weight gain recommendations for twin pregnancies largely stem from studies in the 1990s that didn’t fully account for body composition changes or metabolic differences between women.

In addition, most studies on twin pregnancy nutrition — aside from review articles — are intervention studies that lack a control group, meaning all participants receive nutritional advice where researchers are more or less guessing what might be appropriate nutrition for a twin pregnancy. Then the researchers monitor pregnancy outcomes to determine whether the chosen intervention helped reduce the risk of certain adverse outcomes as compared to existing published data on outcomes in twin pregnancies.

Several researchers have explored the limitations and gaps in twin pregnancy nutrition information. For example, in one study that assessed diet quality and energy expenditure during each trimester in a cohort of women pregnant with twins, it was found that most women did not meet recommended intakes for calories as well as protein. Most women were getting only 70-75 grams of protein per day, which is a far cry from optimal, even in a singleton pregnancy! 

Furthermore, intake of a number of micronutrients were also below recommended levels, including iron, calcium, vitamin D and vitamin B12. They note the following:

Nutrient deficiencies can have serious implications, including increased risks of preterm birth, low birth weight, and developmental issues. Furthermore, supplement use cannot completely replace a healthy diet.  

On top of this, recommendations on prenatal supplementation often don’t reflect newer research on DHA, choline, and magnesium needs.

These studies collectively highlight the scarcity of specific guidelines for energy and nutrient intake in twin pregnancies — and also the frequency of suboptimal intake among women pregnant with twins — emphasizing the need for more targeted research in this area.

I cover more specifics on this in my Twin Pregnancy Nutrition Guide if you want to dive deeper into the findings of these studies.

Many Healthcare Providers Don’t Receive Training in Twin Pregnancy Nutrition

You may be thinking that you can go to any “prenatal” dietitian or nutritionist and get solid advice on twin pregnancies, but that may not be the case. Even among dietitians, nutrition training for pregnancy — and especially twin pregnancy — is limited. Furthermore, many health professionals receive little to no training in nutrition whatsoever!

A 2024 article in the Journal of Women’s Health surveyed OBGYN residents (meaning MDs) on their training in prenatal nutrition — and the results were staggering. When asked about their dedicated pregnancy nutrition-related education, they reported the following:

• Nearly half of these doctors (48%) reported ZERO hours per year of dedicated nutrition-related education
• 49% reported 1–2 hours
• 3% reported >2 hours

Less than one-third of residents reported “feeling comfortable counseling patients on nutrition in pregnancy.” And yet, “Most residents (92%) strongly agreed or agreed that education regarding pregnancy-related nutrition guidelines would be useful for clinical practice.” This survey did not include questions about education in twin pregnancy nutrition, but you can gather from the above data that it probably isn’t sufficient.

And if you think all dietitians are trained in twin pregnancy nutrition, think again. 

As a dietitian myself, I can tell you that the only class that even touched prenatal nutrition was a Lifecycle Nutrition course during my undergraduate studies — and it didn’t cover twin pregnancy. My dietetic internship was heavy on the clinical side, but only included a short rotation on the maternity ward. During my time at that hospital, we didn’t have a single patient admitted who was carrying twins.

I actually surveyed other dietitians to see whether they had training in prenatal nutrition and ¾ reported a similar level of training to me (only a few hours out of their entire 5+ year curriculum). Furthermore, when I asked dietitians whether they felt their training in prenatal nutrition was adequate, 88% reported NO, 12% reported “somewhat,” and 0% reported “yes.” I can only imagine how dismal the statistics would be if I asked about twin pregnancy nutrition specifically.

This is why I built in a whole module on twin pregnancy into the Institute for Prenatal Nutrition^® mentorship program.

Are the Existing Guidelines on Twin Pregnancy Nutrition Any Good?

Well, the existing guidance on twin pregnancy nutrition followed by many clinicians extrapolates from the conventional guidelines on singleton pregnancies. Since calorie needs are higher, they simply adjust portions upwards while maintaining the same macronutrient breakdown.

The Institute of Medicine (IOM), which sets the calorie, macronutrient, and micronutrient goals for singleton pregnancies, does not have separate Dietary Reference Intakes (DRIs) for macronutrients or micronutrients during twin pregnancy. 

But what some intervention studies have done is take the IOM guidance and extrapolate it based on higher caloric needs.

Let me give you an example. Women who are carrying twins are often recommended to consume between 300 to 400 grams of carbohydrates per day. Why so much? Because once upon a time, a research team made the assumption that women pregnant with twins need a certain amount of calories and a certain percentage of those calories to come from carbs (they chose no less than 40%). Therefore, if calorie needs go up, as they do in twin pregnancy, then the carb “requirements” will too. But is that really the case? Not a single study has tested whether these recommendations are actually in the best interest for twin moms.

And to be clear, this likely isn’t the best path forward, given that the risk of gestational diabetes — also referred to as “carbohydrate intolerance in pregnancy” — is much higher in twin pregnancies.

What does this mean for you?

• Your doctor and dietitian are likely relying on outdated or incomplete information.
• You may be told to “just eat more” instead of getting specific recommendations tailored to twin pregnancy.
• You might have to advocate for yourself and seek out additional support from specialists who understand the unique demands of a multiple pregnancy.*

If you follow whatever conventional advice is floating around on twin pregnancy, virtually all of it is an extrapolation of our already outdated and misguided dietary guidelines, just titrated up to larger amounts to account for higher caloric needs — and this is not necessarily “proven” to be what’s best for you and your babies.

* Graduates from the Institute for Prenatal Nutrition® (IPN) are trained in the latest research on twin pregnancy nutrition. There’s an entire module on twin pregnancy! So if your healthcare provider doesn’t seem to be able to guide you on the specifics and you’d like personalized support, consider working with one of these Specialists in Prenatal Nutrition, all lof whom have graduated from the intensive IPN mentorship program. 

Twin Pregnancies Carry Higher Risks — Yet Nutrition Is Overlooked

Twin pregnancies come with a higher risk of complications, including preterm birth, gestational diabetes, preeclampsia, and anemia — yet nutrition, one of the most powerful tools for reducing these risks, is rarely emphasized.

• Gestational diabetes risk is significantly higher in twin pregnancies, yet few studies examine how diet can help reduce this risk. Despite this, carbohydrate-heavy dietary recommendations remain common, potentially worsening blood sugar control.
• Preterm birth is more common with twins, but research on whether targeted nutrition interventions (like omega-3 supplementation or higher protein intake) can help prevent it is lacking, particularly in cohorts of women carrying twins.
• Preeclampsia risk is two to three times higher in twin pregnancies, yet dietary strategies to reduce this risk — such as optimizing protein, magnesium, choline, and glycine intake (just to name a few) — are rarely discussed. Research suggests that nutrition plays a key role in blood pressure regulation and placental function, but twin-specific guidance on preeclampsia prevention are lacking.
• Anemia is more common in twin pregnancies, yet it is often overlooked or diagnosed too late. If it is identified, many providers incorrectly single out iron deficiency, even though anemia can occur due to deficiencies in nutrients other than iron. Anemia can lead to extreme fatigue, dizziness, poor oxygen transport, and increased risk of postpartum hemorrhage. Despite these risks, comprehensive screening for anemia in twin pregnancies is often insufficient, and many women are not advised on how to optimize their intake of the full spectrum of nutrients that supports healthy red blood cell production.

Despite these well-documented risks, nutrition remains an afterthought in standard twin pregnancy care. Instead of being proactive with tailored nutritional strategies, many providers rely on generalized prenatal guidelines that fail to account for the unique demands of a multiple pregnancy. This gap in care leaves many women unknowingly undernourished at a time when nutrition is critical for both maternal health and fetal development.

So, What Can You Do? Practical Steps for Better Twin Pregnancy Nutrition

Since the existing information is lacking, it’s up to you to take an active role in optimizing your nutrition. Here’s how:

• Prioritize protein intake — Protein needs increase during pregnancy, but even more so if you are pregnant with twins. Extra protein is necessary to support fetal growth and to reduce the risk of certain complications for you as well.
• Increase key micronutrients like DHA (from fatty fish or supplements), folate (from liver, legumes, and leafy greens) and iron (from red meat and organ meats). There are others to consider, but this is just a handful of key examples.

• Consume plenty of electrolytes as these support the increased fluid volume in twin pregnancies.

• Don’t rely on a standard prenatal vitamin alone — you may need a more comprehensive prenatal vitamin, plus additional supplementation to meet higher needs.
• Track your nutrient intake rather than assuming “eating for three” is enough. If you need help interpreting whether your dietary intake is adequate, you may want to consult with a well-trained prenatal nutritionist who has experience in twin pregnancy.
• Advocate for lab testing, including screening for iron deficiency or anemia, and keep an eye on your blood sugar levels.

If you need extra guidance, work with a dietitian who specializes in prenatal nutrition (and preferably has experience with twin pregnancies). Graduates from the Institute for Prenatal Nutrition® are trained in the latest research on twin pregnancy nutrition.

Where to Find Evidence-Based Guidance on Twin Pregnancy Nutrition

After working with countless women pregnant with twins, I kept hearing the same frustration: the nutrition advice available just wasn’t enough. That’s why I created the Twin Pregnancy Nutrition Guide — to provide the specific, research-backed recommendations that are missing from conventional guidelines.

The Twin Pregnancy Nutrition Guide is a companion to my book Real Food for Pregnancy. This ebook focuses on the unique nutritional and lifestyle needs of twin pregnancy that builds upon the foundation of knowledge you learned from Real Food for Pregnancy. Without being repetitive to my book, it zeroes in on the specific adjustments you can make to optimize your nourishment while carrying twins.

While I do cover research, the focus of this guide is on the practical application of that information. I don’t just cover the “why” but also the “how.”

It’s designed to support both those who are pregnant with twins and the professionals who work with them, answering some of the most pressing questions, such as:

• What are the different types of twin pregnancies, and what should you know about each?
• How can you adjust your diet to meet the increased nutritional needs of a twin pregnancy? (i.e. What can I eat on top of a typical prenatal meal plan to meet these increased needs?)
• How much more protein is needed and how do I ensure I’m getting enough?
• What does a well-balanced real food meal plan for twin pregnancy look like? 
• Which supplements are most beneficial for supporting a healthy twin pregnancy?
• What’s the optimal amount of weight to gain with twins, and how can you achieve it in a healthy way?
• How can you manage common twin pregnancy symptoms and reduce the risk of complications?
• What nutrition strategies can support postpartum recovery after carrying twins?
• How can you successfully breastfeed twins, and what should you eat to support tandem nursing? Do you need to eat more when tandem nursing?
• What self-care tips can help you stay nourished, energized, and resilient throughout and after your twin pregnancy?

If you’ve found yourself asking any of these questions, this guide is for you! 

I’ve scoured the latest research so you can rest easy knowing that you’re doing everything you can to nourish yourself and your babies in the best possible way.

This guide has everything you need for a healthier, more nourishing (and hopefully easier) twin pregnancy. You can find all the details and grab your copy here.

You don’t have to rely on outdated, generic advice meant for singleton pregnancies. With this guide, you’ll have a clear roadmap to nourishing yourself and your babies — without second-guessing if you’re doing enough.

Final Thoughts

The lack of research on twin pregnancy nutrition isn’t just frustrating — it can impact your health and your babies’ development. 

The reality is that twin pregnancy nutrition is understudied, outdated, and often just plain wrong — but that doesn’t mean you have to settle for inadequate advice or navigate this alone. By understanding the gaps in research, advocating for better care, and prioritizing high-quality nutrition, you can give yourself and your babies the best possible start. 

I’ve summarized the best available research into a practical and easy-to-follow format in my Twin Pregnancy Nutrition Guide.

If you want to feel confident about nourishing your twin pregnancy, my Twin Pregnancy Nutrition Guide has everything you need.

Until next time,

Lily

PS — If you’re a healthcare practitioner looking to better support your clients or patients with twin pregnancies, my Institute for Prenatal Nutrition® mentorship program includes an entire module on twin pregnancy nutrition, diving deep into the research in this area. This program is designed to give you confidence in providing evidence-based guidance as a prenatal nutritionist. You can learn more here.

 

References

• Martin, Joyce A., et al. “Births: Final Data for 2018.” National Vital Statistics Reports, vol. 68, no. 13, 2019, pp. 1-47.
• Institute of Medicine (US) and National Research Council (US) Committee to Reexamine IOM Pregnancy Weight Guidelines. Weight Gain During Pregnancy: Reexamining the Guidelines. National Academies Press, 2009.
• Salomé, Maria, et al. “Exploring Basal Metabolic Rate and Dietary Adequacy in Twin Pregnancies.” Nutrition & Metabolism, vol. 21, 2024, article no. 16.
• Wierzejska, Regina Ewa. “Review of Dietary Recommendations for Twin Pregnancy: Does Nutrition Science Keep Up with the Growing Incidence of Multiple Gestations?” Nutrients, vol. 14, no. 7, 2022, pp. 1389. 
• Hachey, Sara M., et al. “Nutrition education and nutrition knowledge among obstetrics and gynecology residents.” Journal of Women’s Health 33.6 (2024): 741-748.
• Barbour, Linda A., et al. “Gestational Diabetes in Twin Pregnancy: A Call for Action.” Diabetes Care, vol. 42, no. 10, 2019, pp. 1703-1711.
• Carlson, Susan E., et al. “DHA Supplementation and Pregnancy Outcomes.” American Journal of Clinical Nutrition, vol. 97, no. 4, 2013, pp. 808-815.