These Common “Healthy” Foods Were Linked To 60% Lower Fertility Odds
If you're trying to conceive (or just wanting to improve your fertility), the advice can add up quickly—eat this, avoid that, sleep 8+ hours, workout (but not too much!), manage your stress. The list goes on and on.
And while it’s all well-intentioned, it can quickly spiral into overwhelm. Every decision feels amplified, and what started as “eating better” turns into overthinking everything on your plate.
But emerging research is bringing awareness to what truly does make a difference. A recent study 1suggests that the degree to which your food is processed, not its calorie count, not even its macros, may have a measurable effect on your ability to conceive.
And the foods in question aren't just obvious junk food; they include the protein bars, flavored yogurts, gluten-free snacks, and other products that occupy the "healthy" section of your grocery store.
Diet & fertility
In a new study1 from McMaster University, researchers analyzed data from more than 2,500 women between the ages of 20 and 45 who participated in the National Health and Nutrition Examination Survey (NHANES).
This isn’t a small or narrow dataset. NHANES combines in-depth interviews, detailed 24-hour dietary recalls, and lab testing, giving researchers a comprehensive look at participants’ eating patterns, health markers, and overall lifestyle.
The researchers specifically looked at two things: how much of each woman’s diet came from ultra-processed foods, and how closely their eating patterns aligned with a Mediterranean-style diet. They then compared those patterns to self-reported fertility status, defined as trying to conceive for at least a year without success.
Higher intake of ultra-processed foods linked to lower fertility
Women who reported infertility tended to eat more ultra-processed foods, about 31% of their daily intake, compared to those who didn’t report fertility challenges. They also scored lower on overall diet quality.
Even after accounting for age, weight, socioeconomic status, obesity, and other health variables, higher UPF intake was still associated with roughly 60% lower odds of fertility.
That doesn’t mean ultra-processed foods cause infertility. This was an observational study, so it can’t prove direct cause and effect. But the strength and consistency of the association are hard to ignore, especially given how common these foods are in the average diet.
That said, this isn’t about a single food or a single day of eating. It’s about overall patterns over time. Grabbing something convenient when you need it isn’t the issue. It’s what your diet looks like on average, week to week.
It’s not just about calories or weight
Researchers found that the link held even after adjusting for obesity and total calorie intake, meaning this isn’t just about eating too much or gaining weight. There may be something specific about ultra-processed foods themselves that impacts reproductive health.
Researchers point to a few possible explanations. Ultra-processed foods often contain additives, preservatives, and compounds that come from packaging or industrial processing, like BPA, phthalates, and acrylamides. These substances have been linked to hormone disruption in previous research.
There’s also the broader picture of nutrient displacement. Diets high in ultra-processed foods tend to crowd out whole, nutrient-dense options like fruits, vegetables, and healthy fats—foods that support hormone balance and overall metabolic health. And then there’s inflammation. Highly processed diets have been associated with chronic low-grade inflammation, which can interfere with everything from ovulation to implantation.
But again, this isn’t about fear. It’s about awareness. These foods are incredibly common, and they exist on a spectrum. The goal isn’t to eliminate them; it’s to understand their role.
How to shift your diet—without the stress
If you’re reading this and thinking, Okay, now what? The answer isn’t to throw out your whole pantry. A more sustainable approach is to zoom out and look at your overall pattern. Here are a few ways to gently shift your eating pattern:
- Swap one processed snack for a whole-food option. Think fruit with nut butter or plain Greek yogurt instead of a protein bar.
- Upgrade your staples. Choose minimally processed versions of foods you already eat, like plain yogurt instead of flavored or whole grains over refined options.
- Pay attention to ingredient lists. The shorter and more recognizable, the better.
- Focus on addition, not restriction. Adding more whole foods naturally pushes out ultra-processed ones over time.
The takeaway
Fertility is complex. There are so many factors at play—hormones, timing, underlying health, things you can control, and things you simply can’t. Diet is just one piece of that puzzle, and it’s not something that should carry guilt or pressure.
But what research like this does offer is a bit more clarity. It helps us zoom out and see patterns that might be supporting, or working against, our bodies over time.
And if there’s anything to take from this, it’s not to eat perfectly. It’s just to pay attention to the overall direction of your habits. Shifting a little more toward whole, minimally processed foods when you can is enough.