Forget calories in, calories out! If you want to reach your healthiest weight, hormone balance is key. Hormones create a unique chemical symphony that impact how we utilize the calories we take in. There are four hormones key to balance to achieve a healthy weight: estrogen, testosterone, cortisol, and thyroid hormones.
The effect of estrogen on body weight is easily observed by the changes the female body goes through during puberty and menopause. The onset of puberty occurs with rising estrogen levels. During this time, increasing body weight and fat deposition is commonly observed. The onset of menopause occurs with shifting of predominantly active estrogen to less active estrogen. During this time, weight gain is also common, demonstrating that estrogen levels that are too high or too low can contribute to weight gain.
This occurs for several reasons. First, estrogen causes water retention. When you have excess estrogen and diminished progesterone (which helps your body release water), you can gain water weight. Estrogen is stored and made in fat cells so imbalances in estrogen can encourage your body to hold on to fat. This type of estrogen stored in fat produces inflammatory messengers called cytokines that can interfere with metabolic function. Estrogen is also involved in insulin sensitivity - or how well your cells utilize glucose to make energy. Imbalances of estrogen can promote the development of insulin sensitivity and subsequent weight gain. Finally, estrogen is an appetite suppressant so healthy levels are critical for helping manage caloric consumption.
I suspect estrogen imbalances as a factor in weight management in women with longstanding hormone disruptions (such as heavy periods, irregular cycles, or PCOS), women with a history of long term oral contraceptive use, and women who were highly athletic during puberty & experienced resultant irregular cycles.
Testosterone is key in maintaining body composition and supporting development of muscle. Correcting low testosterone levels is an important component in promoting weight loss. However, excess testosterone can promote a condition called androgen excess, in which levels of hormones in the testosterone family are too high, leading to insulin resistance, weight gain, and weight loss resistance. Because testosterone can convert to estrogen, elevated levels of testosterone may also promote weight gain mediated by estrogen dominance.
Cortisol is a hormone that is involved in stress response and balance of blood sugar and blood pressure. Cortisol should be secreted in short bursts to help you respond to stress, then be eliminated. When your nervous system get stuck in a fight or flight response, which can occur from chronic stress, fear, or unresolved trauma, it can lead to long term elevations in cortisol. These elevations tell your body that you are in crisis and your body responds by storing fat. The storage of fat is also also mediated by elevated blood sugar, which is a secondary effect of long term cortisol elevations.
Low cortisol may also play a role in weight gain. Functionally low cortisol can create debilitating fatigue that interferes with our ability to exercise. Low cortisol is also clinically observed to increase consumption of carbohydrate foods. Finally, cortisol is required to activate thyroid hormone and low cortisol may contribute to thyroid dysfunction that promotes weight gain.
Most people are familiar with the effects of thyroid hormone on the body. Almost every cell in the body has receptors that respond to thyroid hormone. Thyroid hormone is integral in maintaining heart rate, metabolism, healthy tissues, and more. Because thyroid helps speed up metabolism, having too little thyroid hormone, a condition known as hypothyroidism can create weight gain. Hypothyroidism can also create fatigue that can make exercise difficulty, further disrupting body composition.
You cannot lose weight without balanced hormones because hormones determine whether our nutrients become fat or fuel, inflammation or energy. Curious about your hormones?
Test don't guess! Here are my favorite hormone tests.
DUTCH Test: A comprehensive hormone panel evaluating estrogen, progesterone, cortisol as well as hormone metabolism
Thyroid Panel: A complete thyroid panel (instead of the TSH your PCP runs) that helps you determine whether your thyroid is performing optimally.