One of the most common side effects of this treatment is the dreaded weight gain . However, as far as we know, there is no clear evidence of this effect.
And yet, there are those who claim that this relationship is real. Why? Doesn't such a drastic hormonal change have a noticeable effect? It certainly does, but not in the way that pop folklore tells us.
What is the relationship between the contraceptive pill and weight gain?
The fact that the “side effects” of contraceptive pills state that overweight is one of them does not help. But the truth is that this statement is not correct in light of the scientific evidence we have right now. But let's start at the beginning: what is a contraceptive pill?
This treatment consists of the administration of a series of pills containing estrogen, progesterone and progestin , roughly speaking . The combination of these hormones varies according to the type of contraceptive pill and the period in which the substances are administered (which does not necessarily have to influence the period of ingestion of the pill). These hormones are metabolically very important for the body.
They are related to general metabolism, but especially to sexual metabolism. Under this premise, it is quite logical to think that the pill can influence weight gain, right? However, this contradicts the studies carried out on the subject. Both progestin pills and combined estrogen and progestin pills have been shown to have no direct relationship with weight gain, according to some interesting meta-analyses, which are reviews that compile the results of many other studies.
According to them, based on clinical trials (conducted studying the treatment in humans), there is no short-term weight gain in any of the cases. In the long term there does not seem to be a relationship either, although the authors make it clear that more research is needed on this subject . In any case, the summary is the following: there is no reason to think, based on what has been observed, that weight gain is part of the side effect of the contraceptive pill.
And yet…
However, many people will say with conviction that they have gained weight. No one is saying that they are lying, of course. What we are saying is that, if nothing were to change, the use of the contraceptive pill does not have to induce weight gain (according to the evidence to date). Although it seems logical to think of the hormonal effect, the truth is that the pills only regulate the concentration of these substances in the blood . So it would be more logical to think that they will do just the opposite.
What about people who have actually gained weight? There could be many explanations. The most likely explanation is that they have changed some lifestyle habits . This is usually because the treatment does have a significant effect on the metabolism. On the other hand, in some cases there could be temporary fluid retention, which would distort the perception.
The most common myths about the contraceptive pill
Weight is a very unreliable and fickle measure. Maybe it's just a misperception. The last point is precisely linked to this: Maybe apophenia (the inherent human tendency to find patterns) is what's playing tricks on us. In any case, we can't blame the pill for fat gain on its own, at least in the short and medium term (although probably not in the long term either).
What does happen: muscle loss
If we continue to look for a hormonal relationship, we may come across this: the contraceptive pill causes less muscle gain. This is what a research team found when trying to elucidate some basic questions about bodybuilding. Specifically, they observed that young women taking the contraceptive pill gained up to 40% less muscle than their male and female peers.
The team's explanation has to do with a hormone called dehydroepiandrosterone, or DHEA. The body produces the hormone dehydroepiandrosterone naturally in the adrenal gland. In turn, dehydroepiandrosterone helps produce other hormones, including testosterone and estrogen . Dehydroepiandrosterone levels peak in early adulthood and then slowly fall as we age.
Furthermore, this hormone is involved in muscle production as it is a precursor to testosterone. Women on contraceptive treatment showed, as analyzed, significantly lower levels of this hormone, which produces less muscle generation. Could this be related, in the long term, to weight gain? It is a possibility.
As we have said on many occasions, the body is very complex and multifactorial. This means that we are subject to an infinite number of variables. Not everyone is affected by the same treatment. At the moment, we have some evidence that is clear, but who knows if we will soon have other evidence that refutes what we think we know so far?