Fertility Diet for Both Partners: What the Research Says

When you start trying for a baby, it is natural to look for foods and supplements that might help. Search results are full of lists promising better egg quality or stronger sperm. The research is more modest, and it points to something often missed: both partners’ health matters. This guide sets out what the evidence actually shows for women and men, which supplements are recommended, which are not proven, and when to talk to your GP.

Why both partners matter

Fertility is often treated as a women’s issue, but about 1 in 3 IVF cycles involve a diagnosis of male infertility, according to Your Fertility, the Australian Government-funded fertility education program. Your Fertility suggests making healthy changes at least three months before trying for a baby. A 2026 study of 2,370 couples planning fertility treatment looked at both partners’ diets and found that healthy eating patterns were linked with slightly more live births, most clearly for women. How partners’ diets work together is still an open question in research, but it makes sense to plan together.

Egg quality: what can and cannot change

Age is the main influence on egg quality. Your Fertility explains that as a woman ages, her eggs age with her, and their number and quality fall over time. Women under 30 have about a 20% chance of conceiving naturally each month, falling to about 5% by 40.

You will often read that eggs take 90 days to mature, so diet in the three months before conception matters most. The follicle that releases an egg does begin its final growth phase about 85 days before ovulation, but that timeline does not prove that food changes egg quality. No food or supplement has trial evidence that it does.

What the research does show is an association between overall eating patterns and fertility. A large study of 17,544 nurses found women with the highest scores on a “fertility diet” had about one third the risk of infertility caused by ovulation problems. It was an observational study, so it shows a link rather than cause. Reviews of the Mediterranean diet in IVF have found mixed results.

Sperm quality: what research suggests

Sperm take about 64 days to develop (Your Fertility rounds this to about three months), so changes take time to show in a semen test. A systematic review of 35 observational studies found that diets including fish and seafood, poultry, cereals and grains, vegetables, fruit and low-fat dairy were linked with better semen quality, while processed meat, full-fat dairy, sugary drinks, sweets and alcohol were linked with poorer quality in some studies. Again, this is association rather than proof.

Other factors with clearer advice: smoking damages sperm (the effect is reversible after quitting), heavy drinking can affect sperm quality, and keeping the testes cool, for example with loose underwear, is recommended.

Supplements: what the evidence says

Our prenatal supplement checker shows what is in the product you are taking.

Alcohol, caffeine and fish

• Alcohol. Australian guidelines advise that women planning a pregnancy should not drink alcohol. For men, heavy drinking can affect sperm quality.
• Caffeine. Your Fertility says there is no clear proof that caffeine affects the ability to become pregnant, and suggests limiting it to 200 mg a day (about two cups of coffee) when trying to conceive.
• Fish. Fish is a good food to include, but Food Standards Australia New Zealand advises women planning pregnancy to limit some high-mercury fish: no more than one 150 g serve a week of orange roughy (deep sea perch) or catfish, or one serve a fortnight of shark (flake) or billfish such as swordfish and marlin, with no other fish in that time.

Weight and fertility

Your Fertility notes that being above or below a healthy weight can make it take longer to conceive, for both men and women. That does not mean drastic dieting. The 2023 International PCOS Guideline points out that healthy habits bring benefits even without weight loss, and warns health professionals about weight stigma. A dietitian can help you find changes that support your health without making food harder.

When to talk to your doctor

See your GP if you have been trying for 12 months, or six months if the woman is older than 35. Go sooner if you have irregular or absent periods, a known condition such as PMOS or endometriosis, or any concerns about either partner’s health. For context, in one German study of women timing sex to ovulation, 68% had conceived within three cycles and 92% within twelve. Healthy Male notes that about half of couples who have not conceived after 12 months do so naturally in the following year. Your GP can also review your supplements and arrange any tests.