Foods to Eat When Trying to Conceive: The Ultimate Fertility Diet Guide

If you're trying to conceive, you've probably already been told to "eat healthily," as if that settles it. It doesn't, not because diet doesn't matter, but because the honest answer is more useful than the vague one: no single food or supplement guarantees a pregnancy, and most of what's genuinely known about diet and fertility comes from studies that show an association, not proof of cause and effect. What the evidence does show, consistently, is that certain overall eating patterns line up with better odds, for both partners, not just one.

This guide is built entirely from real, citable research (the NHS, NICE, Cochrane, and peer-reviewed studies from journals like Human Reproduction and Fertility and Sterility), and it's written with genuinely equal depth for both of you. Most fertility-diet content treats male nutrition as an afterthought paragraph tacked onto a women's meal plan. Sperm and egg quality both depend on what you eat, on roughly the same three-month timeline, so this guide covers both properly, and says plainly where the evidence is strong, where it's weak, and where a popular claim simply doesn't hold up.

If you're currently trying to conceive, we've put together a free TTC Nutrition Guide, written by Sarah, with practical, realistic advice on eating well while TTC, real food swaps, and a calm, non-overwhelming approach.

Get the free TTC nutrition guide

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How Strong Is the Evidence, Really?

Before any specific nutrient or food, it's worth being honest about what "diet affects fertility" actually rests on. A 2023 scoping review in Human Reproduction Update, covering 36 observational studies on preconception diet and female fertility, found that Mediterranean-style eating (plenty of vegetables, fruit, wholegrains, olive oil, fish and legumes, less red and processed meat) had the strongest and most consistent association with fertility outcomes of any pattern studied. But the same review was equally clear about the limits: "due to heterogeneity and the limited available literature on most exposures, there is insufficient evidence to support any specific dietary approach for improving fertility." Read the review.

A 2021 editorial in Fertility and Sterility, bluntly titled "Diet and fertility: take it with a grain of salt?", makes a similar point for clinicians: for most otherwise-healthy people, diet-and-fertility data is genuinely difficult to interpret, and should be treated with real caution rather than presented as settled science. Read the editorial.

None of that means food doesn't matter. Mediterranean-style eating is still the best-supported pattern going, carries essentially no downside, and lines up with general healthy-eating guidance anyway. It means treating any single claim, including some in this guide, as one data point rather than a guarantee, and staying sceptical of anything that promises one specific food will "boost" your fertility on its own.

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The Harvard Fertility Diet: What 17,544 Nurses Told Us

The single most cited piece of diet-fertility research is Jorge Chavarro's 2007 analysis of the Nurses' Health Study II, which followed 17,544 women with no prior history of infertility for eight years as they tried to conceive. Chavarro built a "fertility diet score" from six real dietary factors and tracked it against one specific outcome: ovulatory infertility, not infertility overall. Read the study.

Women following the most factors on the fertility-diet score had a relative risk of ovulatory infertility of 0.34 compared with those following the fewest, roughly a 66% lower risk, a genuinely large difference. The six factors:

• Monounsaturated fat over trans fat
• Vegetable protein over animal protein
• Low-glycaemic-index carbohydrates over refined, fast-digesting ones
• Full-fat dairy over low-fat dairy
• Taking a multivitamin
• Iron from plant sources and supplements over red meat

Two honest caveats worth keeping in mind. First, this is an observational cohort study, not a randomised trial, it shows a strong association, not proof that changing your diet causes this drop in risk. Second, it's specific to ovulatory infertility, a particular hormonal cause, not infertility from other causes like tubal or male-factor infertility, where this pattern wouldn't be expected to help in the same way. And the iron finding specifically hasn't held up as well in later cohorts, some more recent studies haven't replicated it, so treat that one factor as the weakest of the six.

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Her Nutrients: What the Evidence Actually Supports

Here's the nutrient-by-nutrient picture, with what's actually behind each recommendation.

Folate (vitamin B9)

The NHS recommends 400 micrograms of folic acid daily from when you start trying until 12 weeks pregnant, to reduce the risk of neural tube defects. NHS guidance. One outdated claim worth correcting directly: a lot of fertility content still says a BMI of 25 or above alone means you need the higher 5mg prescription dose. NICE's 2025 evidence review looked at exactly this and found no evidence to support high-dose folic acid for a BMI in the overweight or obesity categories on its own, the standard 400mcg dose is enough unless another real risk factor for neural tube defects is present. Read the evidence review. If you're not sure which applies to you, ask a GP or pharmacist rather than guessing.

Vitamin D

The NHS recommends 10 micrograms of vitamin D daily, especially October to March, when UK sunlight isn't enough to make it naturally. A 2018 meta-analysis pooling seven studies in women undergoing assisted reproductive treatment found that those with adequate vitamin D levels had 33% higher odds of live birth than those who were deficient or insufficient (OR 1.33). Read the meta-analysis. That's ART-specific data, from fertility treatment rather than natural conception, but it's a real, meaningful association worth taking seriously either way.

Omega-3 fatty acids

A 2022 US cohort study found that women taking omega-3 supplements had a fecundability ratio of 1.51, roughly 51% higher likelihood of conceiving in any given cycle compared with non-users, after adjusting for age, weight and other factors. Read the study. Oily fish (within the safety limits below), walnuts, chia seeds and flaxseed are the main food sources.

Iron

Iron from plant sources and supplements was one of the six factors in Chavarro's fertility diet score, and was part of that overall RR 0.34 result. As covered above, though, the iron-specific piece hasn't replicated as reliably in later research, so it's worth keeping iron-rich food in your diet as part of a generally balanced pattern, rather than treating it as a guaranteed fertility booster on its own.

Antioxidants

This is the category where marketing outruns the evidence furthest. A 2020 Cochrane review, the most rigorous form of evidence synthesis there is, pooled 63 trials and 7,760 women testing antioxidant supplements (vitamin C, vitamin E, CoQ10 and others) against placebo. The pooled result did suggest a live-birth benefit, but the review's own authors rated the underlying evidence "very low-quality," meaning there's real uncertainty about whether that apparent benefit is genuine. Read the Cochrane review. In practice: eating antioxidant-rich foods (berries, leafy greens, colourful vegetables) as part of a normal diet is sensible and low-risk. Claiming a specific antioxidant supplement will meaningfully "boost egg quality" isn't something the current evidence actually backs.

Soy: the myth worth correcting here

Soy gets avoided by a lot of people trying to conceive, on the theory that its plant oestrogens (isoflavones) might interfere with hormones. A 2015 Harvard study followed 315 women through 520 rounds of assisted reproductive treatment and found the opposite of the fear: higher soy isoflavone intake was positively associated with live birth, 44% in the highest-intake group versus 31% in the lowest. Read the study. There's no good reason, from real human data, to avoid soy foods like tofu, edamame or soy milk while trying to conceive.

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His Nutrients: Equally Important, Rarely Given Equal Depth

Most fertility-diet content treats this as a footnote. It shouldn't be: sperm are newly produced on roughly the same three-month cycle as egg maturation (more on that below), which means his diet in the months before you conceive matters just as much as hers.

The best single summary is a 2017 systematic review in Human Reproduction Update, covering 35 observational studies on diet and male fertility. It found omega-3 fatty acids, vitamins C, E and D, folate, selenium, zinc and lycopene (the pigment that makes tomatoes red) were consistently associated with better semen parameters, alongside low-fat dairy. On the other side, saturated and trans fats, processed meat, full-fat dairy and cheese, and sugar-sweetened drinks were consistently associated with worse ones. Read the review.

What the real trials found

Two actual randomised controlled trials back this up with real intervention data, not just observation. In a 2012 trial, 117 healthy men eating a typical Western diet were split into a group adding 75g of walnuts daily for 12 weeks and a control group avoiding tree nuts. The walnut group showed real improvements in sperm vitality, motility and morphology. Read the trial. Worth flagging honestly: this trial was funded by the California Walnut Commission, an industry funder, which doesn't make the result wrong, but is worth knowing. A separate, independently designed 2018 trial (FERTINUTS), 119 men, 60g of mixed nuts daily for 14 weeks, found similar improvements in sperm count, motility and morphology, plus reduced sperm DNA fragmentation in the nut group. Read the trial. A 2025 meta-analysis pooling this kind of evidence found Mediterranean-style eating was associated with meaningfully better sperm count and motility, though it's worth being precise about what was actually measured: semen parameters improved, but the same analysis found no clear evidence yet for an effect on fertility outcomes like pregnancy or live birth specifically. Read the meta-analysis.

A genuinely new finding: ultra-processed food and male fecundability

Most of the male-fertility evidence above is about semen parameters (count, motility, morphology), not the outcome couples actually care about: getting pregnant. A 2026 analysis from the Generation R Next cohort closes that gap. It found men with higher ultra-processed food intake had lower fecundability (a fecundability ratio of 0.90 per standard-deviation increase in intake) and higher odds of subfertility (OR 1.36), independent of the female partner's own diet. Read the study. That's a genuinely current, real pregnancy-outcome finding, not just a semen-quality one, tying his everyday food choices, ready meals, packaged snacks, sugary drinks, to the actual chances of conceiving.

None of this means cooking two separate meals, or that fertility-friendly eating has to look like a diet plate. In practice it's usually far more relaxed than that, most of what's on the plate above works for both of you, you're just weighting it slightly differently depending on whose priorities you're covering.

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UK Food Safety While Trying to Conceive

Because pregnancy is confirmed weeks after it actually begins, NHS food-safety guidance for pregnancy genuinely applies from when you start trying, not from a positive test. A few of these get watered down or missed on other fertility sites.

• Oily fish: up to 2 portions a week (salmon, mackerel, sardines), and no more than 4 tins or 2 fresh steaks of tuna a week, tuna counts separately because it's higher in mercury than most oily fish. NHS guidance.
• Avoid entirely: shark, swordfish and marlin, their mercury levels are high enough to affect a developing nervous system.
• Liver: avoid liver and liver products, pâté included, they're extremely high in vitamin A, which can be harmful in excess. NHS guidance.
• Unpasteurised or soft-ripened cheese, and non-Lion-mark raw eggs: listeria and salmonella risk. Eggs stamped with the British Lion mark are considered safe to eat raw or partially cooked, others aren't.
• Alcohol: a 2016 Danish cohort study of over 6,000 women found no measurable effect on fecundability at under 14 units a week, but roughly 18% lower fecundability at 14 or more units a week. Read the study. The NHS's standing advice is to avoid alcohol altogether once you're actively trying, the safest option, but this is the real data behind why 14 units is the specific threshold that comes up.
• Caffeine: a 2017 dose-response meta-analysis found no clear association between normal coffee or caffeine intake and natural fertility itself, but the same body of evidence links higher intake, 300mg a day and above, to a real, increased risk of miscarriage. Read the meta-analysis. That's exactly why the NHS's practical 200mg-a-day ceiling, roughly two mugs of instant coffee, still applies once you're trying, not just after a positive test, pregnancy starts well before you know about it.

Shellfish like mussels fits squarely into the safe side of that list, properly cooked and fresh, there's no reason to leave it off the plate.

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Watch: The Fertility Foods That Actually Have Evidence Behind Them

If you'd rather listen than read, here's Dr Natalie Crawford, a US fertility specialist, walking through the fertility foods that have real science behind them. The studies cited in this guide are still what to check any claim against, but it's a solid summary to watch together.

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Why Three Months? The Real Timeline Behind Eating Well Before You Conceive

Diet changes aren't instant. Sperm take roughly 74 days to fully develop from stem cell to mature cell, plus a further couple of weeks to travel and mature, which is why fertility clinicians generally talk about a three-month window for male lifestyle and diet changes to show up in semen parameters. On the female side, the egg that ovulates in any given cycle began its final maturation phase roughly 90 days earlier.

That's also, not coincidentally, roughly the length of the real intervention trials cited in this guide. Robbins' walnut trial ran 12 weeks, FERTINUTS ran 14, and FAZST ran 6 months but measured its main semen outcomes within a similar early window. If you're changing your diet specifically to try to influence egg or sperm quality, three months of consistency is a realistic amount of time to give it before expecting to see, or not see, a difference, not two weeks.

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Fertility Diet Myths We're Retiring

A few specific, named claims that show up constantly in fertility-diet content, and what the evidence, or the lack of it, actually says.

• "Seed cycling regulates your hormones." Seed cycling, eating specific seeds in each half of your cycle, is genuinely popular, but there's no clinical trial evidence it affects fertility or conception specifically. The closest real research, a 2025 systematic review of 10 small studies, looked at seed-based interventions for PMS and PCOS symptoms, not fertility or conception outcomes, and found only modest, low-to-moderate-quality evidence for symptom improvement, with the authors themselves calling for larger trials before any firm conclusion. Read the review. Worth eating the seeds either way, they're nutritious, just not on the promise that timing them to your cycle does anything measurable for conception.
• "Eat different foods in each cycle phase for fertility." A more general version of the same idea, and there's no clinical trial testing phase-timed eating against fertility outcomes at all. A consistently good diet across the whole cycle, not a phase-by-phase plan, is what the actual research in this guide is built on.
• "Superfoods" like maca root or acai for fertility. Popular in fertility marketing, but the human fertility evidence behind both is essentially absent, what exists is largely animal (mouse or rat) studies or manufacturer-funded claims, not real human trials measuring conception or live birth.
• "Men should take zinc and folic acid for fertility." Covered in full above, the FAZST trial (2,370 couples) found no benefit and a real signal of harm, higher sperm DNA fragmentation. This is one of the most repeated pieces of fertility-diet advice online, and one of the most directly contradicted by the best available evidence.
• "Avoid soy, it messes with hormones." Also covered above, real Harvard ART data found the opposite, higher soy intake was associated with better live birth outcomes, not worse.

With those myths cleared up, it's worth being explicit about how much confidence to place in each claim made in this guide.

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When to Seek Help

Diet is one part of a much bigger picture. In line with real NHS guidance on fertility problems, it's worth speaking to a GP if you're under 36 and have been trying for 12 months, or 36 or over and trying for 6 months. It's worth going sooner, regardless of how long you've been trying, if periods are irregular or absent, you suspect PCOS or endometriosis, you've had previous miscarriages, or you already know or suspect a fertility issue on either side.

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Real UK Resources

• British Dietetic Association - Pregnancy and Diet, evidence-based nutrition guidance from registered UK dietitians
• NHS - Foods to Avoid in Pregnancy, the full official list
• Tommy's - Fertility Diet: Nutrition When Trying to Conceive, a UK pregnancy charity's own preconception guidance
• HFEA - UK Fertility Regulator, the independent regulator of UK fertility clinics and treatment
• Fertility Network UK, a national charity offering real peer support throughout TTC

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Frequently Asked Questions

What foods should you eat when trying to conceive?

There's no single magic food, but the strongest evidence points to a Mediterranean-style pattern: vegetables, fruit, wholegrains, legumes, nuts, olive oil and oily fish (within the weekly limits above), alongside monounsaturated fats over trans fats and plant or lean protein over processed meat, for both partners.

Can diet actually improve fertility?

Diet can meaningfully shift the odds. The Harvard fertility diet score showed a large difference in ovulatory infertility risk, and specific nutrients like vitamin D and omega-3 are linked to better outcomes in real studies. But diet alone doesn't guarantee pregnancy, and most of this evidence is observational rather than proof of direct cause and effect.

Does male diet really affect fertility as much as female diet?

The evidence base is smaller than the female-fertility literature, but what exists is real and specific: a 2026 cohort study found men's ultra-processed food intake predicted lower fecundability and higher subfertility risk independent of their partner's diet, and randomised trials (walnuts, mixed nuts) show measurable improvements in semen quality from real dietary changes.

Should men take a zinc and folic acid supplement for fertility?

The best current evidence, a 2,370-couple randomised trial (FAZST), found no benefit for semen quality or live birth, and a real signal of harm, higher sperm DNA fragmentation, in the supplemented group. This is one of the most common pieces of fertility-diet advice online, and one of the most directly contradicted by trial evidence.

How long before trying to conceive should you improve your diet?

Around three months is the realistic window, matching both the real biological timeline, sperm take roughly 74 days to develop and eggs mature over roughly 90 days, and the length of the actual intervention trials behind these recommendations.

Is soy really safe while trying to conceive?

Yes. Real human data, a 2015 Harvard study of 315 women in fertility treatment, found higher soy isoflavone intake was associated with better, not worse, live birth rates. The "avoid soy" advice common on other fertility sites isn't supported by the evidence.

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Keep Reading

Want more support with timing, wellbeing, and next steps?

• Best Time to Get Pregnant: When to Inseminate for Conception
• Stress and Trying to Conceive: How to Cope During Your TTC Journey
• 9 Natural Ways to Boost Fertility
• Male Fertility Screening: What to Expect From a Sperm Test
• Sperm Leakage After Insemination: Is It Normal?
• Two Week Wait Symptoms: What Happens After Ovulation (TWW Guide)

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Food Is Support, Not a Guarantee

There's no meal plan that promises a positive test. What the real evidence supports is something steadier: a genuinely balanced, mostly whole-food pattern, followed by both of you, for a few months, done consistently rather than perfectly. That's a realistic, evidence-backed thing to aim for, not one more thing you have to get exactly right.

You're not behind. You're building something, one meal at a time.