Fertility diet and lifestyle: what the evidence actually says

Trying to conceive · Updated July 2026 · All articles

What a "fertility diet" actually means

Walk into any health food shop or open any parenting forum and you will find confident claims about foods, drinks and supplements that boost fertility. Most of them are not backed by evidence. That does not mean diet and lifestyle are irrelevant to conception; they clearly are relevant. But the reality is more nuanced than the marketing suggests.

No single food or supplement has been shown in robust clinical trials to cause a pregnancy that would not otherwise have happened. What diet and lifestyle choices can do is set favourable conditions: supporting healthy ovulation, egg quality, sperm function and implantation. Think of it as creating a good environment rather than pulling a specific lever.

This matters because the pressure to follow a perfect fertility protocol is real and can add stress rather than support. Understanding what the evidence actually shows lets you focus on the things that are genuinely worth doing, and let go of the rest.

The Mediterranean diet and conception research

Of all the dietary patterns studied in relation to fertility, the Mediterranean diet has the most consistent positive associations. Multiple studies link it with higher rates of natural conception and better IVF outcomes. A large cohort study found that women closely following a Mediterranean-style diet had notably higher rates of successful embryo implantation.

The pattern is worth understanding rather than just copying a meal plan. It emphasises vegetables, legumes, whole grains, olive oil, nuts and fish, with limited red meat and processed foods. The mechanism is thought to involve reduced inflammation, better insulin sensitivity and lower oxidative stress: all of which are relevant to reproductive health.

These are associations rather than proven causal links, so no one can promise that switching to a Mediterranean diet will get you pregnant. But it is a dietary pattern with broad health benefits and no meaningful downsides, so it is a reasonable place to anchor your eating while trying to conceive.

Folic acid: where the evidence is strongest

Folic acid (the synthetic form of folate) is the one preconception supplement with an undisputed evidence base. Taking 400 micrograms daily in the months before conception and through the first trimester reduces the risk of neural tube defects such as spina bifida by up to 70 percent. Neural tube development happens in the first few weeks of pregnancy, often before a positive test.

The recommendation is to start before you conceive rather than waiting for a positive test. If you have a previous pregnancy affected by a neural tube defect, take certain epilepsy medications, have diabetes or a BMI over 30, the recommended dose is 5mg daily rather than 400mcg. Speak to your GP about which dose is right for you.

Some evidence also links folate deficiency to ovulatory infertility, suggesting a role beyond neural tube protection. Eating folate-rich foods (leafy greens, legumes, citrus) alongside a supplement is a sensible approach, since many people do not absorb enough folate from food alone.

Iron, vitamin D and other nutrients worth knowing about

Iron deficiency is common and associated with ovulatory disruption. Some research suggests that non-haem iron from plant sources (found in lentils, beans and fortified foods) may have a more favourable effect on ovulatory function than haem iron from red meat, though a varied diet with adequate total iron is the practical goal for most people.

Vitamin D deficiency is widespread, particularly in regions with limited sunlight. Low vitamin D levels have been associated with poorer IVF outcomes and higher rates of miscarriage in observational studies. A daily supplement of 10 micrograms (400 IU) is recommended through winter in the UK for the general population; higher doses may be appropriate if you are deficient.

B12 is worth checking if you eat little or no animal products, and iodine is relevant for thyroid health, which in turn influences ovulation. A good preconception supplement will cover these alongside folic acid, but it is worth reading the label rather than assuming.

Antioxidants: CoQ10, vitamin E and zinc

Oxidative stress, an imbalance between damaging free radicals and the body's antioxidant defences, can damage eggs and sperm. This is the rationale behind antioxidant supplements. CoQ10 (coenzyme Q10) is the most studied antioxidant for female fertility. Some small trials show improvements in egg quality and ovarian response in women over 35 or those with reduced ovarian reserve, with typical doses of 200 to 600mg daily.

The evidence for CoQ10 is promising but not yet robust enough to recommend it universally. It is considered low risk and is popular among people going through IVF, particularly those who have had poor responses to stimulation. It is worth discussing with your fertility team rather than self-prescribing without context.

Zinc plays a more established role in sperm health than in female fertility specifically. Vitamin E, selenium and other antioxidants appear in many fertility supplement formulations but the evidence for any individual component is weak. Stacking large numbers of supplements without a specific clinical indication is unlikely to help and adds cost and complexity.

What clearly reduces fertility

Smoking is one of the clearest lifestyle factors with a negative effect on fertility in both partners. In women, smoking is associated with reduced ovarian reserve, fewer eggs retrieved in IVF and earlier menopause. In men, it is linked to lower sperm concentration, motility and morphology. The good news is that some of these effects improve after quitting, and quitting is one of the most impactful things either partner can do before starting fertility treatment.

Alcohol has a dose-dependent relationship with fertility. Heavy drinking clearly reduces fertility in both men and women: it disrupts hormone production, lowers sperm quality and increases miscarriage risk. The evidence on low-level drinking is less conclusive, but since there is no established safe threshold for alcohol in early pregnancy either, most guidelines recommend avoiding alcohol altogether while trying to conceive.

A significantly raised BMI is associated with ovulatory disruption, higher miscarriage rates and poorer IVF outcomes in women, and with lower testosterone and reduced sperm quality in men. Even a 5 to 10 percent reduction in body weight in people with a higher BMI can meaningfully improve ovulation and fertility outcomes. This is not about reaching an ideal number; it is about supporting hormone balance and reproductive function.

Exercise: how much is enough and when it is too much

Moderate regular exercise is good for fertility. It supports healthy weight, improves insulin sensitivity (particularly relevant for PCOS), reduces inflammation and is a genuine stress buffer. Around 30 to 60 minutes of moderate activity on most days is broadly consistent with what research supports for overall health and reproductive function.

At the other extreme, very high volumes of intense exercise combined with very low body fat can suppress ovulation through a mechanism called hypothalamic amenorrhoea. This is most common in elite athletes, long-distance runners and people with very restrictive eating alongside heavy training. If your periods have stopped or become very infrequent since you significantly increased your exercise, this is worth discussing with a GP.

For most people, the question is not whether to exercise but whether to ease up slightly on intensity during the two-week wait after ovulation. The evidence on this is not strong, but many people find lower-intensity movement more comfortable and less anxiety-provoking during that window.

Sleep and stress

Chronic sleep deprivation disrupts the hormonal rhythms that regulate reproductive function. Shift workers and people with consistently poor sleep quality have higher rates of menstrual irregularity and some evidence of reduced fertility. Prioritising sleep hygiene during the preconception period is a low-cost intervention with multiple health benefits beyond fertility.

Stress is frequently listed as a major fertility factor, but the research is more modest than the popular narrative suggests. Psychological stress has a small and inconsistent effect on fertility in studies. It can indirectly affect cycle regularity, sexual frequency and treatment compliance, but it is not typically a primary cause of infertility.

This matters because being told to "just relax" is not evidence-based advice and can feel dismissive when you are dealing with something genuinely difficult. If stress is high, addressing it matters for your wellbeing, not as a fertility treatment. Mindfulness, therapy, peer support and simply having your experience acknowledged are all worth pursuing on their own merits.

What you can probably ignore

Fertility teas and herbal blends are widely marketed but there is no good clinical evidence that any of them improve conception rates. Some herbal preparations carry risks if taken in early pregnancy. Applying the same scepticism to expensive supplement protocols without a specific clinical indication is reasonable.

The pineapple core myth (eating pineapple after embryo transfer to support implantation via bromelain) has no meaningful evidence behind it. Eating pineapple is not harmful, but it will not affect the outcome of your cycle. The same applies to most "fertility superfood" claims you will encounter online.

Strict elimination diets that remove entire food groups in the name of fertility are also not supported by evidence and can create nutritional gaps or intensify the anxiety already present when trying to conceive. A varied, whole-food diet is genuinely useful; a perfect, rigidly controlled one is not demonstrably better and is harder to sustain.

Frequently asked questions

Which supplements are actually worth taking when trying to conceive?

The supplement with the strongest preconception evidence is folic acid (400mcg daily, or 5mg if you are in a higher-risk group). Vitamin D is worth taking if you are deficient, which is common. CoQ10 has some evidence for people over 35 or with reduced ovarian reserve. Most other fertility supplements have weak or no clinical evidence behind them.

Is it OK to drink alcohol while trying to conceive?

The safest approach is to avoid alcohol altogether when trying to conceive. Heavy drinking clearly reduces fertility in both partners. The evidence on low-level drinking is less conclusive, but since there is no established safe threshold for alcohol in early pregnancy, most guidelines recommend avoiding it during the conception window.

How much does weight affect fertility?

Being significantly above or below a healthy weight is associated with ovulatory disruption in women and lower testosterone and sperm quality in men. Even a 5 to 10 percent weight reduction in people with a higher BMI can meaningfully improve ovulation regularity and fertility outcomes.

Does stress cause infertility?

Stress is not a primary cause of infertility. It can modestly affect cycle regularity and may influence conception timing indirectly, but the relationship is not strong enough to say that reducing stress alone will resolve a fertility problem. Your wellbeing matters and support is always worth seeking, but please don't blame yourself for being stressed.

Should I take CoQ10 for fertility?

CoQ10 has shown modest improvements in egg quality and ovarian response in some studies, particularly for women over 35 or those with reduced ovarian reserve. The evidence is not yet strong enough to recommend it universally, but it is considered low risk. Typical doses in trials are 200 to 600mg daily; discuss with your GP or fertility specialist.

How much folic acid do I need before conception?

The standard recommendation is 400 micrograms daily, ideally starting at least one month before trying to conceive. A higher dose of 5mg is recommended for people with a previous pregnancy affected by a neural tube defect, those taking certain medications, those with diabetes, or those with a BMI over 30. Ask your GP if you are unsure which applies to you.

This article is for general information only. If you have concerns about your fertility or reproductive health, speak to your GP or a fertility specialist.