What influence do our hormones have?
Progesterone and Estrogen are the two main sex hormones that influence biological processes in the female body. Firstly, they are vitally important to reproductive function. Estrogen catalyzes the development and release of an egg at ovulation (making it possible for you to get pregnant) and progesterone is secreted during the following two weeks to prepare the body to sustain a pregnancy (making it possible for you to stay pregnant). The initial, estrogen-dominant two weeks are known as the follicular phase, while the second two weeks – when progesterone is dominant – are known as the luteal phase. If no pregnancy occurs, both of these hormones decline, menstruation happens, and the cycle begins again.
However, the effects of estrogen and progesterone are far greater than just what is happening in the reproductive system. Sex hormones are one player in the hypothalamic-pituitary-ovarian (HPO) axis. They travel from the ovaries through the blood to the hypothalamus and pituitary gland, where they play a role in physiological and psychological changes that influence our behavior. In this way, changing hormone levels can have an impact on many different aspects of daily life. One place this shows up in our lives is with appetite.
“There is also support that the increased metabolic rate associated with progesterone may increase how much energy one needs, signaling women to consume more foods”
What do estrogen and progesterone have to do with appetite?
Research demonstrates that reproductive hormones play a role in appetite regulation. The estrogen-dominant follicular phase is associated with lower food intake while the progesterone-dominant luteal phase demonstrates reversal of estrogen’s effect, or an increase in appetite (1). This research is shown across the board in studies of animals and humans alike (2). Between the follicular phase and the luteal phase, a difference in calorie intake of 200-600 calories has been noted (1). Specifically, appetite appears to be lowest right before ovulation, to increase during the luteal phase, and to peak at the end of the luteal phase, right before menstruation (3). When a woman does not ovulate, and therefore has little progesterone, no effect is found in eating patterns (4).
Why do estrogen and progesterone affect appetite?
There are a few reasons why this is thought to occur. Food intake is largely regulated by the hypothalamus, which is highly influenced by reproductive hormones through the HPO axis (3). An inverse relationship between food intake and sexual desire has also been shown. This means appetite is lessened in the lead up to ovulation – or prime mating time – and increases again during the following two weeks, when progesterone is working to set up shop for a potential pregnancy (5,6). Another aspect to this is estrogen’s role in the production of dopamine and serotonin and the weakening of ghrelin. Dopamine and serotonin play a role in boosting mood, while ghrelin increases appetite. The research suggests that while mood is high and ghrelin keeps appetite low, women consume less food (3). There is also support that the increased metabolic rate associated with progesterone may increase how much energy one needs, signaling women to consume more foods (7). Interestingly, it is the combination of estrogen and progesterone that causes progesterone to have this effect, which is not found with progesterone alone (4,8). While the “why” requires further scientific exploration, the overall impact of hormonal changes on appetite is well established in research and can be useful when considering our own eating habits across a given cycle.
What can you do with these appetite insights?
By testing progesterone levels with an inne mini lab, women can understand when this shift is occurring and use this to data when making daily choices. While it is important to recognize the influence of these biochemical changes, taking rigid action is unnecessary. As with all nutrition and health information, the foundational knowledge is important and beneficial, but their prioritization and inclusion in decision-making depends on one’s individual needs. We recommend pairing an understanding of hormonal health within the context of a strong relationship between yourself and your body. Radical self knowledge requires both learning the science and holding this information lightly. Once you know the fundamentals, you can take this information wherever you may wish to go.
Appetite provides just one example of how sex hormones can change different aspects of a woman’s life.
1. Rochelle Buffenstein, Food intake the menstrual cycle: A retrospective analysis with implications for appetite research, Physiology & Behavior, Dec.1995, Vol.58, no 6, pp 1067-1077
2. Jill Scneider, When do we eat? Ingestive behavior, survival, and reproductive success, Hormones and Behavior, September 2013, Vol. 64, no 4, Pages 702-708
3. Angelica Hirschberg, Sex hormones, appetite and eating behaviours in women, Maturitas, March 2012, Vol 71, no 3, Pages 248-256
4. J.T. Bisdee, Changes in energy expenditure during the menstrual cycle, British Journal of Nutrition, March 1989, Volume 61, Issue 2, pages 187-199
5. James Roney, Hormonal predictors of sexual motivation in natural menstrual cycles, Hormones and Behavior, April 2013, Vol 62 no 4, pages 636-645
6. Jill Scneider, Metabolic and hormonal control of the desire for food and sex: implications for obesity and eating disorders, Hormones and Behavior, Nov 2006, Vol 50, no 4, pages 562-571
7. P. Webb, 24-hour energy expenditure and the menstrual cycle, The American Journal of Clinical Nutrition, Nov 1986, Vol 44, page 5, pages 614-619
8. Asarian, L., Modulation of appetite by gonadal steroid hormones, The Royal Society, June 2006, Vol 361, Issue 1471, available from: https://bit.ly/2SHdLGd