A patient of mine brought donuts in yesterday for the staff, and I confess! I had the one with sprinkles.

But with the study published in JAMA reporting that 35 percent of U.S. men and 40 percent of U.S. women are obese, I felt the need to talk a little about obesity and reproduction.

The endocrine system is tightly regulated by hormones which provide feedback to the brain to control their own secretion. In order to support a pregnancy, the body needs to interpret caloric status as adequate for sustaining another life. If you think about ancient times, this would be protective against pregnancy in times of famine or epidemic illness. But what happens when things are shifted too much in the other direction? What happens when we are over nourished?

Obesity changes the way our endocrine system functions and how hormones communicate back to the brain. One hormone important in regulating energy and caloric intake is named leptin. Leptin is a hormone secreted by fat cells and acts on the brain to regulate eating and energy balance. Both fasting or exercise decrease leptin levels, while obesity increase leptin. With prolonged increased leptin production (from fat cells) a state of leptin resistance develops.

In short, leptin can no longer communicate to the brain, “Hey, I’m full, stop eating.” The brain becomes accustomed to this higher, constant leptin level seen with obesity, and when an obese person does lose weight, leptin levels decrease and the brain interprets these as abnormally low (compared to the “new normal”). The brain thinks the obese person on a diet is starving, and so a new demand from the brain for more calories is signaled (“I’m hungry”). This is working against efforts to lose weight. Frustrating!

So as you can see, once a person is already obese, it can be hard to lose weight, even with caloric restriction or healthy eating alone. The options include: 1) Intense lifestyle changes which include both diet and physical activity; 2) Medically supervised prolonged caloric restriction; and, 3) Weight loss surgery. I want to emphasize: No plan will be successful without serious lifestyle changes.

And as for reproduction, obesity is associated with increased rates of infertility, miscarriage, birth defects, stillbirth, and other pregnancy complications (including diabetes, preeclampsia, growth restrictions, labor abnormalities, and an increased risk for cesarean section). For infertility, obese patients are much more likely to have anovulatory infertility. This is due to a combination of increased estrogen levels and insulin resistance seen with obesity. Even modest weight loss (5 to 10 percent of body weight) can result in restoring ovulatory abilities (and markedly improve the chance for natural conception). However, even with fertility treatments, obese patients are less likely to have a successful outcome than normal weight peers.

If you are trying to lose weight, please understand it is hard. You need support; so ask for it. Ask for a partner in your plan. Ask your spouse to change their habits too so this can be a lifestyle change. Find some motivation that matters to you (getting pregnant, living a longer life to see your kids/grandchildren, lowering your risk of diabetes, heart disease, cancer, etc.). You can do it, you just need help. So ask for it. Life is short, live the best version you can.

And if you are a health care provider (or one in training), this is on us. I know from experience that this conversation is not easy to have. Patients do not like to talk about obesity. But listen, every obese patient knows this a problem. We need to bring it up. Start the conversation. Talk to patients about this. Make obesity a real problem instead of ignoring it. Change does not happen without support and motivation. We all said we wanted to “help people” when we decided to work in healthcare. So do it, help your patients.

Natalie M. Crawford is a reproductive endocrinology and infertility physician.  She can be reached on Instagram @nataliecrawfordmd.

Image credit: Shutterstock.com