Intermittent fasting can help you lose weight, improve your cardiovascular health, and even reduce mealtime prep. However, some dieters reported irregular menstrual cycles and difficulty managing blood sugar. So is intermittent fasting safe for women? If you are considering this method of diet control, there are strategies that may reduce the risk of health problems.
Feast and Fast
Despite being a popular way to diet, intermittent fasting is hardly new. Abstaining from food has long been connected to religious observances including during Ramadan, Lent, and Yom Kippur. It is also a component in some non-religious practices and even used in sports –– especially wrestling as a way to “make weight.” Unlike most diets, intermittent fasting quickly becomes part of a lifestyle rather than a short-term weight loss strategy. Part of its success is because proponents report an easier time sticking with it than with other diets. Because it is about when you eat rather than what you eat, the diet’s lack of restrictions can be helpful for anyone struggling with a regimented program. Of course those who spend non-fasting hours consuming cupcakes won’t get the same benefits.
Although there are several intermittent fasting plans, the most common is the 16/8 method. In this program, dieters eat for eight hours a day. Over the remaining 16-hour period, they abstain. Although strict religious fasts often prohibit water, in this program water is not only acceptable but encouraged. Some practitioners also drink coffee or other sugar-free caffeinated beverages during the fasting period but try to restrict sugar and alcoholic drinks to the eight-hour time frame. One study of males who combined weight training with the 16/8 method showed they reduced fat and kept muscle. Since the weight lost by dieters is often as much as 25% muscle, this is not insignificant. Since studies like this one often focused on men, the question of whether or not intermittent fasting is safe for women is important. Unfortunately, while much has been written about gender disparity in medical studies, even in 2020 it remains a problem. One examination of 71 studies found in Harvard’s database for intermittent fasting found that only 13 included women.
Whether it’s a 16-hour fast or even 18 hours, studies suggest it works by triggering a metabolic switch from glucose-based to ketone-based energy. Ideally this means your body will stop storing fat and rely on glucose stored in the liver. Ketogenic diets imitate starvation. While our bodies will normally store fat during long periods without food, brief periods may trick them. The challenge is that men and women evolved differently. Men tended more toward hunting, women toward gathering. This evolutionary quirk makes women predisposed to fat storage during periods of hunger while generally larger males get a metabolic boost. This has been demonstrated in studies of intermittent fasting.
Another intermittent fasting plan involves restricting food completely for one or two days per week. In the 5:2 diet , you restrict your calories to around 500 on two non-consecutive days of the week. Examined ten years ago, this type of program was connected to reduced insulin sensitivity and fewer problems with blood sugar among ten healthy males. Again the question of whether or not intermittent fasting was safe for women wasn’t addressed. However an older study showed that men benefited while women had worse issues with blood sugar. There is also anecdotal evidence that women who began intermittent fasting reported irregular menstrual cycles. This is not terribly different from women who reported either heavier flows or missed periods after starting a vegan diet.
Despite the challenges, recent research shows that because of the ketogenic benefit regular fasting periods can lead to improved disease resistance as well as better overall mental and physical health and improved mental and physical performance. These benefits –– along with weight loss, make intermittent fasting worth checking out for women as well as men. The best strategy applies to all diets or fitness regimens: patience. Returning to your favorite health club after a long absence might motivate you to overdo it. Unfortunately, overexerting yourself can lead to extreme soreness at best and an injury at worst. Either way, you won’t be motivated to return to your workout for days, maybe weeks. Intermittent fasting is the same thing. Start slowly. If you plan to restrict your eating daily, then start by fasting for twelve hours. Do this for a week or two. If it doesn’t affect your energy, blood sugar, or menstrual cycle then slowly extend the time period. If you never reach 16 hours, don’t feel bad. Many have reported success using a 14/10 program. Intermittent fasting isn’t meant to be a short-term strategy to lose a couple pounds. It’s a lifestyle. So taking the time to make sure it works for you will make you more likely to stick with it. Generally anyone who is pregnant, breastfeeding, or has had an eating disorder should avoid these types of diets, but if you pay attention to your body, intermittent fasting can be safe for women.
- Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males.
- Effects of intermittent fasting on health, aging, and disease.
- Intermittent Fasting and Human Metabolic Health.
- Glucose tolerance and skeletal muscle gene expression in response to alternate day fasting.
- Research on intermittent fasting shows health benefits.
John Bankston is a published author of over 150 nonfiction books for children and young adults including biographies of Jonas Salk, Gerhard Domak, and Frederick Banting.