Food Aversions in Early Pregnancy: What Causes Them?

Food aversions in early pregnancy are caused by the rapid hormonal changes that occur after conception — particularly the sharp rise in HCG and oestrogen that follows implantation. These hormones directly affect the senses of smell and taste, making certain foods and smells suddenly overwhelming, repulsive or completely unappealing.

Oestrogen is the primary driver. This hormone enhances sensory perception significantly in early pregnancy — heightening the sense of smell and altering how taste receptors respond to certain flavours. Foods that previously had a mild or pleasant smell can suddenly have an intense, overwhelming odour that triggers an immediate aversion response. The smell and taste of food are closely connected, which is why a smell aversion and a food aversion often go hand in hand.

HCG is also thought to play a role, which would explain why food aversions tend to be most intense in the first trimester when HCG is rising most rapidly and improve for many women as they enter the second trimester when HCG plateaus. There is also an evolutionary theory that food aversions in pregnancy serve a protective function — causing pregnant women to avoid foods that could potentially contain harmful substances or pathogens at a time when the developing embryo is most vulnerable.

Food aversions can begin surprisingly early in pregnancy — some women report noticing them as early as 7-14 DPO, around the time of implantation and the initial rise in oestrogen and HCG. For many women, a sudden and unexplained aversion to a previously enjoyed food or drink is one of the first signs they notice that something might be different about that cycle.

For most women, food aversions become more pronounced in the weeks following a missed period as hormone levels rise rapidly. They tend to be most intense in the first trimester — typically between 6 and 12 weeks pregnant — and improve for many women as they enter the second trimester, though some women find aversions persist throughout their entire pregnancy.

The timing of food aversions can vary significantly between women and even between pregnancies in the same woman. Some women develop aversions very early and find them one of their most prominent symptoms, while others experience them mildly or not at all. Both experiences are completely normal.

A food aversion in early pregnancy is more than simply not fancying a particular food — it is an often visceral and immediate repulsion that can be triggered by the smell, sight, thought or taste of certain foods. For many women it feels completely involuntary and can come on very suddenly.

The experience varies in intensity. Some women describe a mild distaste for certain foods that makes them unappetising. Others describe an intense, almost physical revulsion that can trigger immediate nausea — sometimes just from catching a whiff of a triggering food from across the room. The latter is particularly disorienting when the food in question is something the woman previously enjoyed.

• An immediate feeling of repulsion when smelling or thinking about certain foods
• Nausea triggered instantly by the smell or sight of a triggering food
• Foods that previously tasted pleasant suddenly tasting strange, bitter or overwhelming
• Being unable to be in the same room as certain cooking smells
• Developing a sudden strong dislike of foods that were previously favourites
• The thought or mental image of certain foods triggering nausea
• Finding previously enjoyed flavours too intense, too sweet or too savoury
• Gagging or retching in response to certain smells or tastes

While food aversions in early pregnancy are highly individual — what one woman finds unbearable another may tolerate easily — there are certain foods that come up again and again as common triggers across the TTC and pregnancy community. Understanding the most frequently reported aversions can help you make sense of what you are experiencing.

Meat — particularly raw or cooking meat — is one of the most commonly reported food aversions in early pregnancy. The smell of meat cooking is frequently described as overwhelming and nauseating, and many women find themselves unable to prepare or eat meat in the first trimester even if they previously had no issue with it.

Coffee is another extremely common aversion, which many women find particularly difficult given their reliance on it before pregnancy. The smell of coffee — which most people find pleasant — can become intensely repulsive in early pregnancy. Fish and seafood, eggs, strong spices and heavily seasoned food are also widely reported triggers.

• Meat — particularly raw or frying meat, one of the most common aversions
• Coffee — a very frequently reported aversion despite being previously enjoyed
• Fish and seafood — strong smell makes it a common trigger
• Eggs — both raw and cooked eggs are commonly reported
• Strong spices and heavily seasoned foods
• Garlic and onions — particularly when cooking
• Greasy or fried foods
• Alcohol — many women develop a strong aversion before knowing they are pregnant
• Strongly flavoured cheeses
• Fast food and processed foods with strong artificial flavours

Developing a sudden and unexplained aversion to a food or drink you previously enjoyed — particularly if it appears alongside other possible early pregnancy symptoms — is one of the more distinctive early signs that some women experience before a missed period.

Unlike symptoms such as fatigue or breast tenderness which have obvious non-pregnancy explanations, a sudden and specific food aversion that is completely new is harder to attribute to PMS or other causes. Many women in the TTC community describe a sudden inability to stand the smell of coffee or meat in their TWW as one of the things that made them suspect they might be pregnant before testing.

However, food aversions before a missed period are not universal — many pregnant women do not experience them until later in the first trimester, and some do not experience them at all. The absence of food aversions before a missed period does not rule out pregnancy.

Understanding when pregnancy-related food aversions can realistically begin helps to give context to any changes you are noticing during the TWW. Here is a rough guide by DPO:

• 1-5 DPO: Food aversions at this stage are not pregnancy related. Implantation has not yet occurred and pregnancy hormones are not present.
• 6-8 DPO: Implantation is occurring and oestrogen is beginning to rise. Very early food aversions could theoretically begin around this point in some women.
• 9-10 DPO: HCG is rising after implantation. Some women report the first hints of food aversions or changes in taste preferences around this time.
• 11-12 DPO: HCG and oestrogen are rising rapidly. A sudden aversion to a previously enjoyed food at this stage alongside other symptoms may be an early sign.
• 13-14 DPO: Around the time of a missed period. Food aversions that have developed or intensified as your period would normally be due lean more toward early pregnancy.
• After missed period: Food aversions that persist and intensify after a missed period are a well recognised first trimester symptom as hormone levels continue to rise.

Food aversions and food cravings are two sides of the same coin in early pregnancy — both are driven by the same hormonal changes that alter smell and taste perception, and many women experience both simultaneously. While certain foods become repulsive, others can become intensely appealing in a way that feels compelling and urgent.

Interestingly, many women find that their cravings and aversions are at opposite ends of the flavour spectrum. Women who develop an aversion to strongly flavoured or savoury foods often find themselves craving mild, bland, starchy foods — toast, crackers, plain pasta, cereal — that are gentle on the stomach and do not trigger nausea. Women who develop an aversion to sweet foods may crave savoury alternatives.

This pattern of craving mild, easily digestible foods alongside an aversion to strong flavours is thought to be partly driven by nausea management — the body directing women toward foods that are less likely to trigger vomiting and more likely to stay down. Working with these cravings and aversions rather than against them is often the most practical approach to nutrition in the first trimester.

For some women, food aversions in early pregnancy are so severe that eating becomes genuinely difficult. When almost every food triggers nausea or revulsion, maintaining adequate nutrition in the first trimester can feel like an impossible challenge.

It is important to know that for most women the first trimester is not the time to worry about eating a perfectly balanced diet. If the only things you can tolerate are plain crackers, toast and mild fruit, this is completely acceptable for a few weeks. The developing embryo in the first trimester is very small and its nutritional requirements are modest compared to later in pregnancy.

The most important things to prioritise when food aversions are severe are staying hydrated, taking a prenatal vitamin when you can tolerate it, and eating whatever you can manage without triggering nausea — even if the variety is extremely limited. This will not harm your baby and will not last forever.

While food aversions and the nausea they trigger are a normal part of early pregnancy for many women, there is a point at which they can become a medical concern that needs attention.

Hyperemesis gravidarum — severe pregnancy sickness that goes beyond typical morning sickness — affects a small percentage of pregnant women and can cause inability to keep any food or drink down, significant weight loss, dehydration and electrolyte imbalances. If you are unable to keep fluids down for more than 24 hours, are losing significant weight, feel dizzy, are urinating very little or have dark urine, it is important to seek medical attention.

Signs of dehydration — dark urine, dry mouth, dizziness and reduced urination — should always be taken seriously in early pregnancy. Staying hydrated is more important than eating when food aversions are severe, and if you cannot keep fluids down you need medical support.

• Unable to keep any food or fluids down for more than 24 hours — seek medical attention
• Significant weight loss in the first trimester
• Signs of dehydration — dark urine, dry mouth, dizziness, reduced urination
• Feeling too weak or unwell to carry out daily activities
• Vomiting blood or bile
• Any concerns about your ability to maintain adequate nutrition or hydration

For women going through IVF, food aversions in the two week wait after a transfer are one of the more potentially meaningful symptoms to notice — largely because they are not a commonly listed side effect of the progesterone supplementation used in IVF cycles.

Unlike fatigue, breast tenderness and bloating which are all direct effects of progesterone medication, food aversions are more specifically associated with rising HCG and oestrogen levels. This means that a genuine food aversion after an IVF transfer — particularly a sudden aversion to a previously enjoyed food — may carry slightly more weight as a potential early indicator than some other symptoms.

However, it is still not a reliable enough sign to draw conclusions from. The stress and anxiety of the IVF two week wait can affect appetite and food preferences in ways that are not related to pregnancy. The only reliable answer comes from a blood test or home pregnancy test at the appropriate time.

Managing food aversions in early pregnancy is largely about working with your body rather than against it — eating what you can tolerate, avoiding triggers where possible, and finding ways to meet your nutritional needs within the constraints of what is currently acceptable to you.

Identifying your personal aversion triggers is the first step. Once you know which foods, smells and environments are most likely to cause a reaction, you can take practical steps to minimise exposure. Asking a partner to take over cooking duties, avoiding the kitchen when certain foods are being prepared, and choosing foods that are served cold — which produce less smell than hot food — can all significantly reduce aversion-triggered nausea.

Eating small, frequent meals of foods you can tolerate helps to keep blood sugar stable and prevents the empty stomach that often makes nausea and aversions worse. Keeping plain, easily digestible snacks nearby at all times — crackers, plain biscuits, mild fruit — means you always have something acceptable to reach for when hunger strikes but nothing else appeals.

• Identify your personal trigger foods and avoid them where possible
• Ask a partner or family member to take over cooking if cooking smells are a trigger
• Choose cold foods over hot — they produce less smell
• Eat small frequent meals to keep blood sugar stable
• Keep plain snacks nearby at all times — crackers, plain biscuits, mild fruit
• Stay well hydrated — prioritise fluids even when food is difficult
• Try eating foods at room temperature rather than hot
• Ginger in various forms — tea, biscuits, sweets — can help manage nausea alongside aversions
• Do not force yourself to eat foods that trigger a strong aversion — work with your body

For most women, food aversions are at their worst in the first trimester and begin to ease as they enter the second trimester around 12-14 weeks. This improvement coincides with HCG levels plateauing and the body adjusting to the elevated hormone environment of pregnancy.

Many women find that foods they could not stand the sight or smell of in the first trimester become completely acceptable — or even enjoyable — again from around 14-16 weeks. Some women find their food preferences return almost entirely to normal, while others find certain aversions persist throughout pregnancy.

A small number of women experience food aversions throughout their entire pregnancy, which can make nutrition and meal planning a significant ongoing challenge. If this is your experience, working with a midwife or dietitian who understands pregnancy nutrition can be very helpful in ensuring your nutritional needs are being met within the constraints of your aversions.

If you are experiencing a sudden food aversion that is new and unexplained — alongside other possible early pregnancy symptoms — taking a pregnancy test at the right time is the most reliable next step.

The earliest most sensitive pregnancy tests can detect HCG is around 10-12 DPO, but for the most accurate result it is worth waiting until the day of your missed period and testing with your first morning urine. FMU is the most concentrated of the day and gives the best chance of detecting low levels of HCG in very early pregnancy.

If you test and see a very faint line do not dismiss it. A line that appears within the reading window of the test — no matter how faint — is still a positive result. Retest in 48 hours and the line should be noticeably darker as HCG levels continue to rise.

A faint line on a pregnancy test after food aversions and other early symptoms is incredibly common — HCG levels are still low in the early days after implantation and the line on a test can be almost impossible to see even when you are genuinely pregnant.

Enhancing your test photo by adjusting brightness, contrast and using a red light filter can make even the faintest lines much easier to see. Saving your tests and comparing them side by side over several days is also hugely reassuring — a line that gets progressively darker confirms that HCG is rising as it should.

ClearLine is an iOS app that uses AI to analyse your pregnancy test photo and detect even the faintest lines. It includes image enhancement tools, a gallery to save and track all your tests over time, and a side by side comparison feature to help you watch the line progression — everything you need to make sense of those early uncertain results.