For many people, starting a family is a goal of the highest order. For some it's their lifelong calling, for others it's a life milestone they want to meet, and for many it's something they've long expected to do.
That makes it all the more difficult when, after trying for months or even years, you're unable to successfully conceive. There is any number of possible reasons for this, so it's no surprise when people turn to anything they can to give themselves a higher chance.
One such possible option is the fertility diet. Can a diet really affect your fertility, though? What even is a fertility diet, anyway? And does it work, or is it just a way for people to sell ebooks and supplements?
What Is a Fertility Diet?
A fertility diet is nothing new, not really. Books have been written about the subject for decades, with varying levels of complexity and varying advice. The idea behind them is relatively simple: some foods presumably boost fertility, and others inhibit it. By making appropriate dietary choices, you may be better able to conceive.
So what is a modern fertility diet, specifically? Here's what you should (supposedly) eat and not eat.
Eat more fruits and veggies. Fruits and veggies are nutritious, natural, and filling. A Harvard study found a correlation between ovulation disorders and higher levels of carbs, trans fats, and animal proteins. Thus, eating less of those – via eating more fruits and vegetables – should improve fertility, right?
Well, one thing to remember is that correlation is not necessarily causation. Diet definitely impacts a lot of areas of your life, but studies can be performed to "prove" pretty much anything as long as you ignore certain variables. We'll talk about that more later.
Regardless, fruits and vegetables are great to eat in any diet. Fruits are full of natural sugars to keep you going, and they're packed with antioxidants and nutrients your body needs to stay healthy. Vegetables, meanwhile, are extremely good. They're full of fiber, packed with vitamins and minerals, and even the chlorophyll is well-used in the body.
Eat more healthy fats. Healthy fats are things like the oils found in nuts, avocados, and olives. They're unsaturated fats, which your body needs for energy. There may be some evidence that suggests these natural fats boost conception rates during the IVF cycle, though how that plays into natural conception is another subject entirely.
Eat less unhealthy fats. Trans fats in particular are pretty bad for your body, though they may not be entirely as bad as health scares in the 80s and 90s made them out to be. They're not going to immediately kill you the way some old PSAs would have you believe, but they're certainly not great for you.
In particular, trans fats can build up insulin resistance in the body, and that can lead to prediabetes or diabetes. Any broad-spectrum health issue in your body is going to cause issues with everything from your sleep quality to your chances at conception and miscarriage, so you want to avoid getting these kinds of diseases whenever you can.
Eat more complex carbohydrates. Some people claim all carbs are bad, but sugar is a carb, and sugar is naturally present in just about everything. The fruit is healthy, but it is also packed with sugar and thus carbs. How do you reconcile this? Well, some people go full Keto, while others don't worry so much about it.
Carbs actually fall into a few different categories. You can think of them as "slow" and "fast" carbs, or simple and complex carbs. Complex, "slow" carbs are long chains of molecules, which take the body a long time to break down and use to their full extent. One big source of these complex carbs is dietary fiber, in things like whole grains and vegetables.
Fiber is great for a few reasons. It slows down your digestive system, allowing your body to more fully process what you eat. It's packed with vitamins as well. Additionally, when your digestive system is slower, you feel full sooner and eat less, which means you aren't going to be spiking your blood sugar as much and you'll be more likely to lose weight or maintain a healthy weight level.
Eat fewer simple carbs. The inverse of the previous section is the simple, fast carbs. These are things like processed white flour, processed sugar, white rice, and baked goods. The more heavily processed the ingredients are, the more the fibers have been broken down. This means your body can digest them more easily, but it also means they go through you faster and have a worse impact on your blood sugar.
Eat less red meat. Red meat tends to be fairly fatty, and those fats aren't always very good for you. While red meats and white meats are full of protein and minerals to help keep you healthy, there are also some fears of issues with animal hormones in the meat. There's no much evidence to back up these fears, but that's more due to lack of study than definitive proof.
Eat more fish. Fish, especially fatty fish like salmon and tuna, are the inverse of red meat. The fat in them is super healthy and packed with omega-3s, and the fish is a great source of protein that doesn't carry the same risks as land animal protein. 
One thing to watch out for here is that you're getting your fish from a healthy source. There's a lot of concerns about fish farming, which not only results in lower quality fish, it also runs the risk of heavy metal poisoning via mercury, which hurts you AND your potential unborn child.
Eat more full-fat dairy. Oddly enough, many nutritionists agree that full-fat dairy is better for pregnancy than low-fat dairy or dairy alternatives. Low-fat dairy has some correlation to infertility, though again, this hasn't entirely been studied. One potential cause is calcium, which is more present in full-fat dairy than in other dairies, and which is extremely important in conception and pregnancy.
It's also beneficial to get probiotics to help regulate your system. Yogurt and kefir are both great options for this, filling the role of both dairy and probiotics. Don't go overboard with them – they're full of lactose, a sugar – but a serving or two a day is still a good idea.
Watch what you drink. A lot of common beverages can have a negative impact on your overall health and thus your fertility.
- Soda: packed full of sugar and virtually zero useful nutrients.
- Coffee: caffeine can make it more difficult to conceive and keep a pregnancy, so cut back on it or cut it out entirely.
- Alcohol: while a single glass of wine a day is considered healthy in some circles, alcohol of any stripe is anathema to pregnancy. Cut off drinking entirely as soon as you decide you want to try to become pregnant.
Be careful of soy products. Natural soy, like edamame or miso, is generally fine. Processed soy, like soy milk, is probably worse for you.
People will often warn you of "phytoestrogens" in soy having a negative effect on you, but don't worry about that. The phytoestrogen scare is primarily fueled by ultramasculine and insecure men who see "estrogen" and get scared. The molecules are completely different and won't interact with your natural hormones.
Get more iron. In fact, in general, it's a good idea to take a balanced multivitamin each day when you're trying to become pregnant. This is very real: a Harvard study specifically focused on the impact of a multivitamin on fertility found that taking folic acid supplements were 40% less likely to experience ovulatory infertility over eight years. 
So there you have it: a general overview of a fertility diet. In broad strokes, it's similar to other healthy diets. Eat more of the healthy foods, eat less of the unhealthy foods, improve your overall bodily health, and have an easier time conceiving a child. You have a lot of flexibility in terms of what you eat within these categories, too, so you aren't restricted to buying meals from specific stores or restricting yourself to only a few dishes for months at a time. That makes it a relatively easy diet to follow, especially compared to something like a pure vegan or keto diet.
Can Diet Affect Fertility?
You might have noticed something about the dietary advice above: it's all generic. In fact, literally any "how to eat healthier" advice is going to cover pretty much all of the same beats. Less bad fats, more good fats, less sugar, more fruit, less processed ingredients, more vegetables, less red meat, more fish.
Here's the thing: diet, overall, impacts your health. Your health, in this case includes everything from your cardiovascular system to your blood sugar regulation to your hormone levels. Dysfunction in any of these systems can disrupt your natural bodily function, which includes everything from your metabolism to your sleep to your chances of becoming pregnant.
Pregnancy is very hard on the body. The mother's systems adjust dramatically to develop and support new life, and will happily destroy itself if the baby gets a chance to survive. Keeping it supported while growing a child is extremely difficult, which is why you have near-weekly pre-natal appointments and constant monitoring of your health when you're pregnant. 
Eating a healthy diet does several things.
- It improves your overall bodily health through the consumption of vitamins, minerals, and nutrients while excluding negative nutrients.
- It helps you lose weight or maintain a healthy weight. Obesity is a massive cause of dysfunction in the endocrine, immune, and cardiovascular systems, all of which need to be healthy for a successful pregnancy.
- It broadly reduces bodily inflammation and the presence of free radicals, which negatively impact health in a variety of ways.
- It can reduce the risk of something like PCOS, though, in fairness, you'd need to be eating a healthy diet for years beforehand for this to truly matter; if you already have PCOS by the time you're trying to get pregnant, it's too late to "cure" it with diet.
It helps to think of it not as fighting your body to try to conceive against all odds, but rather to support your body to get it into a state where it's willing to conceive. Your body, once pregnant, will happily devote itself to the developing child rather than your own health. However, before you become pregnant, it will fight pregnancy if it's unhealthy enough that becoming pregnant would be a major risk. It's not, you know, intentionally doing this, but that's one way to think of the situation.
You need to get your affairs in order before you can help another, essentially. By eating a healthy diet, you get yourself into a healthy state and can focus on becoming pregnant.
Now, should you buy into a pregnancy diet plan? That's really up to you. How willing and able are you to stick with a diet? Sometimes, the structure of an external meal plan with supplied ingredients or even a cookbook can be helpful. Sometimes not. A lot depends on your self-control and your starting position. If you're 10 lbs overweight, it'll be easier to adjust than if you're 100 lbs overweight.
In general, though, just eat healthier, cut back on the junk, eliminate caffeine and alcohol, and you'll put yourself in a better position to conceive. There's not a lot more to it, when you dig into the specifics.
