In recent years, the intermittent fasting diet has been taking hold and, with its various variations, would seem to actually be able to make you lose weight. However, attention must be paid. In fact, intermittent fasting in women alters hormonal balance. So let's try to understand the risks and benefits of this diet, discussing the results of a very recent research published in the journal Obesity by an American team from Northwestern University and the University of Illinois (Kalam et al, Obesity, Oct 2022).
Intermittent fasting, what it is
Obesity is a condition that, in the long run, can increase the risk of cardiovascular disease, diabetes, depression and cellular degeneration. This is why it is important to combat obesity by trying to follow a healthy, varied diet without excesses and an active lifestyle. In recent years, a type of diet has taken hold, intermittent fasting, which consists in alternating, with moments in which we eat, moments of fasting. There are several variations of intermittent fasting. For example, we talk about the warrior diet, in which you have a window of four hours a day to eat without counting calories and then you should drink only water until the next day. Another, more attenuated variant, provides for the possibility of eating without restrictions for 8 hours a day and then fasting for the next 16 hours. Or you can choose two non-consecutive days a week in which you fast while on the other days you eat without limitations. The results obtained would seem to give reason to this type of diet, as we are actually witnessing a weight loss. The problem, however, is that this is a fairly recent diet, and therefore not much studied. In addition, given its easy applicability, it makes DIY easy. It is therefore clear that intermittent fasting must be deepened to understand what effects it has on the body, in addition to weight loss, and to whom it could be addressed. The research we are talking about today sheds light on an aspect that should not be overlooked, the action of intermittent fasting on the hormonal system.
Intermittent fasting alters female hormones
Scientists recruited 23 women, 12 premenopausal and 11 postmenopausal, all with a condition of obesity. For 8 weeks the volunteers were asked to follow the warrior's diet, that is, to eat without counting calories for a window of 4 hours a day and then, until the next day, to drink only water. Before, during and at the end of the experiment, the participants in the study underwent medical examinations and blood tests. What emerged was that, at the end of the study, all women had lost weight, losing between 3% and 4% of their body weight, as well as reducing insulin resistance and oxidative stress markers. However, a hormone called dehydroepiandrosterone or DHEA was decreased by about 14%. DHEA is produced by the adrenal glands and is then converted into the sex hormones estrogen and androgens, it reduces with age and DHEA-based supplements are recommended by doctors both to improve fertility in those seeking pregnancy and to counteract the processes of aging affecting the ovaries in more mature women. The DHEA values in any case remained within the recommended levels but the result is noteworthy. In fact, in premenopausal women this reduction could affect fertility and it is necessary to evaluate the risk-benefit relationship between a reduction in DHEA and body weight loss. For postmenopausal women, this reduction adds to the physiological decrease in DHEA and estrogen.
Intermittent fasting, the analysis of the results
As mentioned in the introduction, intermittent fasting is a diet that has only recently gained fame and whose effects have not yet been well understood. Today we know that it has beneficial effects on weight loss but alters the hormonal balance. This effect still needs to be assessed in depth on a larger sample of people and over a longer period of time. Then, as regards the benefits observed in the management of blood sugar, the topic is much debated. In the case of the current study, which studied obese women, a reduction in insulin resistance was observed while a previous study conducted on people of normal weight or overweight, but not obese, observed that, in women but not in men, intermittent fasting increases insulin resistance (Heilbronn et al, Obes Res, 2005).
Conclusions
Intermittent fasting can be useful in losing weight in case of obesity but care must be taken if you are not obese. In addition, it is necessary to evaluate your health situation well, considering the possible presence of a pre-existing condition of insulin resistance. Clearly, intermittent fasting should be avoided if you have an eating disorder or a history of this. In any case, the result of what emerges from these considerations is that it is always necessary to ask an expert for advice, avoiding do-it-yourself. While intermittent fasting may seem easy to follow, it is essential to evaluate its effects on the body with a doctor, based on each person's personal history, because intermittent fasting is not for everyone and the risk of altering blood sugar and hormones is real.
