How Weight May Be Impacting Your Fertility
Many of our patients are surprised to learn just how much their weight may be impacting their fertility. According to the American Society for Reproductive Medicine (ASRM), an estimated 12% of all female infertility issues are weight related, split relatively evenly between women who weigh too much for their frames, and women who weigh too little (or who have too little fat stores).
Overweight / underweight women suffer from infertility at a rate approaching double that of their healthier-weighted peers. The Harvard Nurses’ Health Study — a large, long-term research project looking at a variety of health topics — found that overweight women took twice as long, and underweight women nearly four times as long to get pregnant as their healthier-weighted counterparts. And it doesn’t take a lot: just a 10% departure from a healthy BMI is enough to generate an unwanted impact on fertility.
Men also face weight-related fertility challenges, with heavily overweight men 50% more likely than their healthfully-weighted counterparts to struggle with infertility. And couples where both partners are overweight? They are three times more likely to go a full year of trying for pregnancy without conception as are their more healthfully-weighted peers.
The impact of weight on fertility is the result of a constellation of factors that are difficult to tease apart from one another. Estrogen certainly plays a role— it is made in fat cells, so the more fat cells we have the more estrogen we produce. Increased estrogen prevents ovulation (part of the mechanism of birth control pills), and is reflected in the higher likelihood that overweight women struggle with irregular or infrequent periods, or periods without ovulation or with inadequate ovulation. Being overweight increases androgens, or “male” hormones, which likely also plays a role. Estrogen-producing fat cells generate inflammatory substances, and excess weight also contributes to an increase in insulin levels, both of which can impact fertility.
On the flip side, underweight women (or women with too little fat stores) tend to have too little estrogen. Inadequate nourishment lowers FSH and LH levels, which leads to low estrogen levels, which leads to follicles that can’t develop properly, inadequate or lack of ovulation, and irregular cycles. Low estrogen levels can also lead to reduced fertile cervical mucous. It may not be obvious to you that your fertility issues may be related to your weight, as being as little as 10% underweight can adversely affect your sex hormones.
Here’s the good news: the vast majority of women who are struggling with weight-related infertility will conceive naturally once their weight stabilizes in a more healthful place. This is true for 75% of overweight women who lose a bit of weight, and for 90% of underweight women who gain some. The even better news? Sometimes all it takes is a small bit of momentum in the right direction: a weight loss of just 5% or weight gain of just 2-3 pounds can be enough to make a difference, and to begin to change the hormonal cascade from one preventing pregnancy to one promoting it.
So, maintaining a healthy body mass index (BMI) is one of the most helpful things you can do to support your fertility. What is a healthy BMI? Doctors tell us that a BMI between 19 and 25 is ideal, calculated by taking your weight in pounds, dividing it by your height in inches, dividing it by your height in inches again, and then multiplying the result by 703. (Example: 140 pounds, divided by 67 inches, divided by 67 inches, multiplied by 703 gives you a BMI of 22.)
Exercise is of course, part of the BMI picture. Some women need to move more; others need to move less.
Food choices, quality, and quantity are also front and center. Our baseline food mantra at The Origin Center is the following (from food writer Michael Pollan):
Eat real food. Not too much. Mostly plants.
From there, we modify depending on the unique individual we see in front of us, and her or his particular circumstances. Some ground rules to get you started:
Your schedule:
Eat actual meals at regular intervals and avoid snacking. (see below)
Your approach:
Eat real food. Reduce or eliminate all processed foods from your diet. Would your great-grandmother recognize this as a food item? Did all of the ingredients grow from the earth or come from the sea, or eat other things that grew from the earth or came from the sea, with minimal intervention? If the answer is yes, great, have at it. If the answer is no, then while the item you’re about to put in your mouth may be supremely delicious, it’s not actually food, and it doesn’t support your health or your fertility.
Not too much. Eat actual meals of fresh, warm, cooked food, and stop snacking. Will your blood sugar plummet without a snack? Do you get ravenously hungry, tired, shaky, or moody with unclear thinking if you go more than a few hours without eating? That’s a sign your blood sugars are out of balance and need attention. The real solution is not to eat more often. The solution — and one that will support your fertility more in the long-run — is to balance your blood sugars at a deeper level through a conscious change in food choices.
Mostly plants. I am not (nor is Chinese medicine) ever going to claim that a vegetarian diet is automatically a “healthier” one (in fact, eating more meat is one of the most important changes some women can make in support of their fertility), but it is true that vegetables are the foundation of healthy eating, across the board. Include more in your diet, especially dark green leafy and cruciferous vegetables like chard, kale, collards, turnip greens, spinach, cabbage, broccoli, cauliflower, kholrabi, and brussels sprouts. Do this especially if you are overweight, have been diagnosed with PCOS or metabolic disorder, or are known to be estrogen-dominant.
Also consider significantly reducing or eliminating entirely the following: wheat flour (breads, pastas, crackers), refined sugar and products containing it (desserts, baked goods, cakes, ice cream), and dairy (especially non-organic or non-pastured dairy) from your diet, across the board. As a general rule these food items are pro-inflammatory and can negatively impact fertility.
All of this being said, at The Origin Center, we take a non-judgmental approach to weight. We engage in this discussion because of what the overwhelming evidence suggests regarding weight and its impact on fertility, but we do so in the service of knowledge and empowerment; we so do without any shaming or blaming, and we do so in full support of unabashed reveling in whatever gorgeous fleshy container you’ve been gifted with inhabiting.
Ready for some support on your health or fertility journey?
Your initial consultation is always free — come meet us in person to learn more.