Wellness Wednesday  ·  5 min read

What to Eat to Keep Healthy: The Foods the Evidence Actually Backs

Nutrition advice online is noisy, and most of it isn't backed by much. So rather than another generic "eat more vegetables" list, we went to the research on dietary patterns and health outcomes  including reproductive health, since that's where some of the strongest recent evidence sits to see what actually holds up.

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The pattern with the strongest evidence: Mediterranean-style eating

Harvard Health’s review of fertility and diet reached a similar, unglamorous conclusion: a healthy pattern (Mediterranean-style, folic acid, B12, omega-3s) beats a miracle food. Of all the dietary patterns studied, a Mediterranean-style diet has the most consistent research behind it — not just for heart health, but for reproductive outcomes too. A 2023 systematic scoping review looking at dozens of studies on preconception diet found that higher adherence to a Mediterranean pattern was more strongly and consistently linked to improved pregnancy rates than any other dietary factor studied. An earlier study of couples undergoing fertility treatment found that higher adherence to this pattern was associated with a meaningfully greater chance of pregnancy.

The pattern itself is simple:

• Vegetables, fruit, and legumes — the daily foundation
• Whole grains over refined carbohydrates
• Olive oil as the primary fat source
• Fish and poultry in moderation, red and processed meat kept low
• Minimal added sugar and ultra-processed snacks

What to cut back on, according to the same research

The same scoping review found that reducing trans fats, saturated fats, and discretionary foods like fast food and sugar-sweetened drinks was linked to better outcomes across several studies arguably as useful a lever as adding "superfoods" in.

The nutrients worth paying attention to — and the NHS vitamins and minerals overview / RCOG pregnancy vitamin-supplement leaflet if you want the UK public-health version

A few individual nutrients keep showing up across the research as particularly relevant:

• Folate and B vitamins — one well-cited study linked higher Mediterranean-pattern adherence to better folate and B6 status, which in turn correlated with pregnancy outcomes
• Antioxidants — diets rich in antioxidant-containing foods (berries, leafy greens, nuts) are consistently associated with reduced oxidative stress, a factor relevant to both egg and sperm quality
• Omega-3s — found in oily fish, and associated in prospective research with healthier developmental markers

Fertility and healthy diets

The link between diet and fertility isn't a fringe idea — some of the largest, longest-running nutrition research in the world has looked at it directly. Harvard's Nurses' Health Study II followed over 17,000 women and found that those who adopted a cluster of specific dietary and lifestyle habits had a substantially lower risk of ovulatory infertility than those who didn't  a difference of roughly sixfold between women following five or more of these habits and those following none.

The habits that made the biggest difference in that research included:

• Swapping some animal protein for plant protein beans, nuts, and legumes in place of a portion of meat
• Choosing full-fat dairy over low-fat a counter-intuitive one that shows up repeatedly in ovulatory infertility research
• Favoring slow carbohydrates  whole grains and vegetables over refined, high-glycemic carbs
• Getting enough iron particularly from plant sources and supplements rather than red meat alone
• Taking a multivitamin  associated with lower ovulatory infertility risk across the same cohort

None of this is about extreme restriction  if anything, the research points the other way. It's a small number of specific, swappable choices layered on top of the same overall pattern already linked to long-term health: more plants, better fats, steadier blood sugar, and less ultra-processed food.

The longevity link

This isn't just about the next few months, either. In 2024, a Harvard-led study followed over 25,000 women for up to 25 years and found that those who most closely followed a Mediterranean-style pattern had up to a 23% lower risk of dying from any cause over that period, with benefits showing up for both cancer and cardiovascular mortality specifically. Researchers linked part of this to measurable improvements in inflammation, insulin resistance, and blood fat levels — not just abstract "healthy eating," but changes that show up in bloodwork.

Earlier meta-analyses pooling data across many longevity studies found a similar pattern: consistently lower cancer incidence and cancer mortality among people with high adherence to this way of eating. And in older adults specifically, ongoing reviews of the evidence link sustained adherence to reduced cardiovascular events into later life.

The connecting thread across the fertility and longevity research is the same: chronic inflammation and oxidative stress accelerate cellular aging and are also linked to poorer egg and sperm quality. A diet that consistently lowers both isn't doing two separate jobs — it's doing one job that happens to matter at every life stage.

You don't need a strict meal plan. Research on adherence to these patterns suggests consistency matters more than perfection — most of the studied benefit comes from the overall pattern of what you eat most days, not from any single "perfect" meal.

We follow the evidence, not the hype.

Thanks for reading — Jade & Yan, founders of