There’s an old joke that all it takes for a man to lose 10 pounds is to stop drinking soda, while women spend a lifetime trying to shed just a small percentage of their body weight. While this specific scenario is greatly exaggerated, there are differences between how men and women gain and lose weight. In general, women have a slower metabolism than men due to less lean muscle mass and higher body fat percentage.
Different body types include different hormonal profiles, and women experience weight loss and the effects of intermittent fasting differently than men. While most research and literature defaults to the experience of intermittent fasting in men’s bodies, there are particulars to a woman’s experience that deserve to be addressed.
This article explores the unique metabolism of women over the course of their lives, and how intermittent fasting can help women prevent weight gain, and lose weight when needed.
Women’s Metabolism and Weight Gain
While both men’s and women’s metabolism may be influenced by stress, lack of sleep, and severe diets in which calories are restricted, evidence shows that women gain weight in response to these scenarios at a higher rate than men do.
According to the American Psychological Association, while men and women report roughly the same stress levels, women are more likely than men to report that they eat in response to stress (31% vs. 21%), and are less likely than men to exercise (24% vs. 35%). This is supported by Cleveland Clinic findings which show women are more likely to gain weight in response to stress than men are.
Research also shows that sleep loss affects women more than men. A 2008 study from Duke University found that women who report insufficient sleep tend to be more overweight than men in the same predicament and are at greater risk for type 2 diabetes and heart disease than men are.
Women are more likely than men to diet, which can lead to weight retention when caloric restriction is too high. Women’s bodies are also more sensitive to this caloric restriction than men’s. Extreme caloric restriction in women can have adverse effects on menses and fertility, in addition to other negative hormonal consequences.
Stress and lack of sleep aside, a woman’s body goes through normal hormonal changes over the course of their lives, which plays a role in metabolism changes. Hormonal profiles are different during menstruation, pregnancy, pre-menopause, menopause, and post-menopause.
Intermittent Fasting, Weight Loss and Fertility
Women of menstruating age require a certain percentage of body fat to maintain normal menses and fertility. When caloric restriction is too high, the body may respond by holding onto the fat you’re attempting to lose, thus negating the positive outcome of any diet. In the case of too much fat loss, infertility or amenorrhea can occur.
Amenorrhea is a potentially serious condition in which a woman of childbearing age fails to menstruate. Not only does failure to menstruate make you infertile, but amenorrhea is associated with hormonal imbalances that can lead to weight gain, thyroid malfunction and osteoporosis.
For women concerned with fertility, intermittent fasting could potentially increase irregularities in reproductive cycles and even cause a reduction in ovary size. While this has been proven the case in animal studies, comparable human studies have yet to be done.
It’s important that women who partake in an intermittent fasting protocol continue to consume sufficient calories for healthy, regular menstruation. For this reason, a lighter fasting protocol is often recommended. For example, fasting for shorter periods of time, or fewer days.
Losing Weight While Being Pregnant
Pregnancy is not the time to start thinking about weight loss. Both excessive weight gain and excessive weight loss are associated with negative outcomes in pregnancy. In fact, pregnant women who are at a healthy weight should consider a daily increase of 300-500 calories during their second and third trimesters. A weight gain of 10-40 pounds is healthy depending upon the starting weight and body fat percentage of the mother.
If you haven’t done intermittent fasting before, pregnancy is not the best time to experiment. Due to the ethics of subjecting a pregnant woman to a health study with unknown outcomes, research on the effects of any type of diet while pregnant is limited and whether or not intermittent fasting is safe during pregnancy remains to be studied. The best way to manage pregnancy weight is to combine a healthy diet with extra physical exercise.
How Menopause Affects Metabolism
Beginning with pre-menopause around the age of 40, a woman’s metabolism starts to slow down and body fat shifts towards the abdomen. Belly fat is notoriously difficult to lose and is also closely correlated with type 2 diabetes, high cholesterol levels and high blood pressure. While women are not as prone to heart disease as men, heart attacks in women are more often fatal.
On average, menopause begins at age 51. With this change in hormones, women over 50 tend to experience greater difficulty sleeping, painful joints and slower metabolism, all of which can lead to weight gain.
Intermittent fasting is safe for women who are not trying to get pregnant and can help combat many of the hormonal changes and associated weight gain that occurs as we age.
The most common benefits of intermittent fasting for women are listed below:
- Weight loss: Intermittent fasting is effective for weight loss in both men and women.
- Decrease abdominal fat: Intermittent fasting reduces body fat in general and is effective in reducing the abdominal fat that many women find increases with age.
- Preserve muscle mass: Intermittent fasting can help preserve muscle mass that most women lose with age, something that traditional caloric restriction does not do. This is, in part, due to fasting’s stimulation of human growth hormone.
The Best Intermittent Fasting Schedule for Women To Begin With
With all of the above taken into consideration, the best intermittent fasting schedule for women may depend upon your age, and you body condition. Fasting is not recommended for women who are already underweight or have struggled with disordered eating in the past.
The following examples show how intermittent fasting protocols can be modified for beginners or women concerned about fertility:
The 16:8 is a popular style of intermittent fasting that entails a 16-hour fasting window, followed by an 8-hour eating window. Fasting is normally done overnight. To modify this particular fast, you could begin with 12:12. Stay there to keep the fast mild, or move toward a 14:10 fast if you feel comfortable.
A 5:2 fast is a week-long protocol that entails five days of normal eating, interspersed with two days of fasting. The two fasting days don’t normally take place at once but are spread throughout the week. To begin with a modified version, try a 6:1 fast. On your once-weekly fasting day, you could limit your caloric intake to 25%, or roughly 500 calories, instead of completely abstaining from food.
Regardless of the choice you make, start slow, listen to your body and pay attention to how you are feeling, especially if intermittent fasting is new to you. Be kind to yourself if you aren’t feeling great on your fast, and be willing to make changes as needed. It’s important not to be so strict that your diet overrides your intuition.
IF Can Improve Your Health When Done Correctly
Intermittent fasting has many benefits and is unique in that it’s not about caloric restriction. During the eating window, continue to take in enough calories for optimal health. When done correctly, intermittent fasting not only leads to weight loss in women but can lead to a greater sense of health and well-being and improved body image. Something that women everywhere can appreciate. To avoid mistakes and achieve better results please refer to our complete guide to Intermittent Fasting and weight loss.