The Role a Woman's Hormones Play in Body Composition
Let’s talk about sex…hormones! Does it surprise you to know that a woman’s body makes testosterone? It’s true – but the amount circulating in men’s bodies is 15-20 times greater. Testosterone at higher levels not only dictates hair and muscle growth, but how fat is stored – which is why men tend to carry weight in their midsection, and women subcutaneously and in the butt and thigh areas.
Healthy fat storage levels are around double in women what they are in men – thanks to estrogen, and the ability to conceive children, we keep some extra around! And it starts early, even before puberty. Around age 8, girls' bodies begin to store more fat per adipose cell than boys, even though total number of fat cells usually remains the same.
“Estrogen,” in fact, isn’t one hormone, but actually a class of three – estrone, estradiol, and estriol. Estradiol is the one with the biggest impact, one of which it exerts through its interaction with another hormone: insulin. Too little estradiol, and insulin resistance increases, meaning blood glucose is harder to control and fat storage increases. A healthy lifestyle comprised of a well-balanced diet, exercise, stress management, and quality sleep can promote hormone balance. During menopause, drastically changing levels of estrogen may be to blame for weight gain, but imbalances earlier on can be a problem too – most younger women don’t need to get levels checked, but if you have issues with menstruation, infertility, or menopausal symptoms, it’s something to bring up with your doctor.
These differences all contribute to differences in metabolism – because men have higher testosterone and more muscle, they burn more calories at rest even if height, weight, and activity levels are the same. There are ways to boost metabolism (without crazy supplements or extreme measures!), but most of them come back to the basics of good nutrition: hydration, a focus on protein, and exercise that increases heart rate and builds muscle.
Aside from a difference in hormones, there are some key nutrients women need more of, despite being generally smaller with slower metabolisms.
- Calcium. Women’s bodies are most absorptive of calcium and promote bone-building during adolescence, which is crucial, since differences in hormones and muscle mass mean women are at a higher risk of fractures later in life.
- Vitamin D. Required for proper absorption of calcium, this one is important for the same reasons, but hard to get from food. Get 10-15 minutes of sunlight on arms and legs daily so your body makes it for you!
- Iron. Since most of the body’s iron is stored in the blood, menstruation causes losses monthly. That’s why women of child-bearing age are recommended to get 3 times the amount of iron through diet or supplementation!
- Folic Acid. One of the B vitamins, it is crucial pre and during pregnancy to prevent neural tube defects like spina bifida. Start taking a supplement a few months before trying to become pregnant to make sure you’re stocked up.
- Fiber. Despite being smaller in sizes, women actually have longer digestive tracts than men. This means absorptive surface is increased, and cultivating a healthy microbiome is even more crucial. Women are twice as likely to have IBS, which could also be influenced by hormones and stress levels. Getting enough fiber can help keep things regular.
This week is National Women’s Health Week – celebrate, support, and care for women in your life (or yourself!) by doing something extra (popping up with a healthy snack?) or even just necessary (like maybe schedule that annual check up?).
Sarah Waybright MS, RD is the owner and founder of WhyFoodWorks and the team dietitian for Vegetable and Butcher. WhyFoodWorks does nutrition education through food in Washington, DC in corporate seminars. Vegetable and Butcher is a subscription-based service that delivers chef designed, dietitian approved, thoughtful prepared meals to health-conscious people in Washington, DC. You can find Sarah on Twitter, Facebook, Pinterest or Instagram to get food and nutrition tips - and of course, healthy recipes.