For generations, morning sickness has been seen as one of the less glamorous parts of pregnancy, a rite of passage most pregnant women endure in their first trimester. Traditionally, it’s been chalked up to hormones, stress, or just “one of those things.”
But now, some researchers are looking in a new direction: Could certain proteins be partly responsible for morning sickness and other pregnancy symptoms? The answer may surprise you and could change the way we look at prenatal care, nutrition, and maternal health.
[ez-toc]
Let’s explore this developing area of research and what it could mean for expectant parents. Protein And Pregnancy Nausea
What is Morning Sickness?
Morning sickness refers to the nausea and vomiting experienced by up to 70–80% of pregnant women, usually during the first trimester. Despite its name, it can strike at any time of day, and for some, it lingers well beyond the first few months.
It’s believed to be caused by a combination of:
- Rising levels of hormones (especially hCG and estrogen)
- Heightened sense of smell
- Slower digestion
- Fatigue and stress
In most cases, it’s unpleasant but manageable. However, in severe cases, it becomes hyperemesis gravidarum—a condition that can lead to dehydration, weight loss, and hospitalisation.
The New Hypothesis: Protein’s Role in Morning Sickness
Traditionally, morning sickness hasn’t been causally linked to diet, it’s more often thought of as a symptom that influences diet, not the other way around. However, new research is challenging that idea.
A recent study published in Nature examined a hormone called GDF15 (Growth Differentiation Factor 15), which has been associated with both appetite suppression and nausea. It’s naturally present in the body but rises sharply during pregnancy.
What’s fascinating is that GDF15 levels vary significantly between individuals and appear to be influenced by protein consumption and liver function. In short, your body may react more strongly to GDF15 during pregnancy if it hasn’t seen much of it before, particularly in the presence of high protein levels.
You may also like: Best Thing About Being Pregnant
The GDF15 Connection: Protein And Pregnancy Nausea
Here’s where it gets interesting:
- GDF15 is produced by the placenta in early pregnancy.
- Some women are genetically more sensitive to GDF15.
- Women with low baseline GDF15 levels (i.e., before pregnancy) tend to feel sicker when levels rise suddenly.
What does this have to do with protein?
Researchers believe that the protein composition of your diet before and during pregnancy can influence how your body processes GDF15. In animal studies, increasing dietary protein led to increased GDF15 levels and associated nausea symptoms.
This doesn’t mean protein is “bad” during pregnancy, but it may help explain why some women are hit harder than others.
Protein: A Double-Edged Sword?
Protein is essential during pregnancy. It supports:
- Fetal growth and tissue development
- Maternal blood supply expansion
- Hormone and enzyme production
But if your body is sensitive to GDF15, and protein intake boosts GDF15 further, then protein-rich foods might worsen your nausea, especially in the first trimester.
This could explain why:
- Many women develop food aversions to meat, eggs, or dairy early in pregnancy.
- Carbohydrate-heavy foods (like crackers or toast) are often better tolerated.
- Protein aversions are common even among normally health-conscious eaters.
So while protein is crucial, the type, timing, and quantity may need to be adjusted for those struggling with morning sickness.
Other Pregnancy Issues Linked to Protein Sensitivity
The potential impact of protein and GDF15 may extend beyond just morning sickness.
Researchers are exploring connections to:
- Loss of appetite in early pregnancy
- Food aversions (especially to animal protein)
- Low maternal weight gain
- Higher risk of severe nausea (hyperemesis gravidarum)
It’s possible that the body, to protect itself or the fetus, signals strong aversions to high-GDF15-triggering foods, mainly high-protein items. This could be part of an ancient survival mechanism.
You may also like: Bathe Kids to Get More Sleep
What This Means for Expecting Parents
If you’re pregnant and struggling with nausea, this information doesn’t mean you should eliminate protein. But it does suggest you might benefit from tailoring your intake, especially in early pregnancy.
Here are some practical tips based on the research:
1. Focus on Gentler Proteins
Try lighter, less odorous protein sources, such as:
- Greek yogurt
- Nut butters
- Soft tofu
- Protein-fortified cereals or oats
- Plant-based protein shakes
These may be easier on your stomach than meats or eggs.
2. Eat Small, Balanced Meals
Large meals can trigger nausea. Instead:
- Eat every 2–3 hours
- Combine carbs with protein and fat to maintain blood sugar
- Avoid going too long without eating (which worsens nausea)
3. Experiment with Timing
You may tolerate protein better at certain times of day. Some women do better with:
- Carb-heavy breakfasts
- Protein-rich snacks later in the day
Track what works best for you.
4. Try Cold or Room Temperature Foods
Hot foods often have stronger smells, which can trigger nausea. Cold options like smoothies, cheese sticks, or chilled lentil salads may go down more easily.
5. Don’t Force It
If the thought of meat or eggs turns your stomach, listen to your body. Most people can make up for protein intake later in pregnancy when nausea subsides.
What About Supplements?
If you’re worried about your protein or nutrient intake, talk to your healthcare provider about:
- Prenatal vitamins (most cover essential amino acids and B vitamins)
- B6 supplements (often recommended for nausea)
- Protein powders (opt for pregnancy-safe, unsweetened options)
Remember, food aversions and nutrient gaps are common in the first trimester. Short-term adjustments are unlikely to harm your baby, as long as you stay hydrated and nourished as best you can.
Should You Get Tested for GDF15?
At this stage, testing for GDF15 sensitivity or levels isn’t routine in prenatal care, but that may change as research progresses.
For now, it’s more useful as an explanation than a diagnostic tool.
If you have a history of hyperemesis gravidarum or unusually severe nausea, it might be worth discussing with your provider, especially if you’re considering future pregnancies. New therapies that target GDF15 are already in early clinical development.
The Bottom Line
Morning sickness is incredibly common—and incredibly misunderstood. The emerging link between protein intake, GDF15, and nausea is exciting because it offers a possible scientific explanation for something that’s long been written off as “just part of pregnancy.”
More importantly, it empowers you to make informed dietary choices. If protein-heavy meals make you gag or meats suddenly seem unbearable, it might not be all in your head—it could be your body’s natural way of coping with biochemical changes.
So give yourself grace, trust your instincts, and know that:
- Morning sickness isn’t your fault
- It usually fades by the second trimester
- Your baby will get what they need, even if you’re eating mostly toast and ginger tea for now
