Do Birth Control Pills Make You Fat

How the pill changes your body shape

(Epitome credit:

BBC/Getty

)

Many women believe that the pill tin crusade weight proceeds. Research hasn't plant this – but it has found that it tin alter torso shape (and fat storage) in other surprising ways.

Information technology'south been blamed for polluting our rivers, destroying our marriages and – ironically – killing our sex drives. It's been chosen a conspiracy by the patriarchy. It'south even be accused of making women fancy ugly men. Merely for many women, one of the most off-putting charges against the contraceptive pill is that it makes us fatty.

In fact, weight gain is the most normally reported side upshot of the combined pill – the virtually popular blazon, which contains both lab-made oestrogen and progesterone. This is why pharmaceutical companies listing it on the packet.

But after several decades of research, there still isn't any conclusive prove that the outcome is existent. The largest review so far examined 49 studies of the combined pill and found "no large effect is evident", but also that in that location wasn't plenty well-conducted research to be sure. The researchers found this is true no affair what type of progesterone the combined pill contained (for more than on the dissimilar kinds of pill, bank check out this article). Other studies that looked at progesterone-only pills similarly have found little prove of an event.

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Maria Gallo, an endocrinologist at Ohio State University who co-authored the review, believes our belief in the pill-weight connectedness is downwardly to a natural homo bias. People are experts at finding patterns all effectually usa, even where at that place are none. The phenomenon, known as apophenia, is the reason we may find it easy to compare peppers to politicians, run across the faces of Harry Potter villains staring down at us from the clouds, or read likewise much into past lottery numbers. We're particularly susceptible to apophenia if we've been primed to expect a certain issue – such as gaining weight afterward starting a new medication.

"It's the same reason why in that location'southward this thought that vaccines tin can cause wellness bug," says Maria Gallo. "If you give them to a population, you're going to have some people who accept health bug, whether they're linked to the vaccine or not."

Researchers haven't found evidence that the pill causes weight gain – but they have found that it can change a woman's body shape and body fat percentage (Credit: Getty/BBC)

Researchers haven't constitute evidence that the pill causes weight gain – only they have found that it can change a woman's torso shape and trunk fat per centum (Credit: Getty/BBC)

In the case of the pill, Gallo points out that the average person puts on just over a pound (half a kilo) of weight each yr for most of their life, starting in early machismo – which, incidentally, is when near women start using contraception. It may exist reassuring to be able to arraign this 'weight creep' on something other than overeating; last year she even caught women in the deed of inventing weight proceeds after being fitted with the contraceptive implant.

Even so, it's non all in our heads. Though large-scale reviews oasis't establish that the pill causes weight gain, it can change a woman'southward body shape and composition.

In that location are three big reasons for this, and they have to do with muscle, fluid retention, and fat.

Muscle in

Back in 2009, Steven Riechman, an practise physiologist at Texas A&M University, discovered 1 surprising impact of the pill, entirely by accident.

At the time, he was researching how a person'due south genetic makeup tin affect their power to grow their muscles through exercise. His research squad put a grouping of men and women through 10 weeks of resistance training – slow, punishing exercises such as crunches and lifting heavy weights. Then participants were weighed to see if they had more muscle than they started with. The squad also gathered information on various lifestyle factors so that they could make sure any gains were caused by genetics and non, for example, the medications they were on.

While they were doing this analysis, they discovered that women on the pill had gained 40% less muscle than those who weren't on information technology.

"It jumped out as a pretty large affect," says Riechman.

8 women open up well-nigh the side effects they experienced from the pill. Watch the video below.

Information technology'due south well-known that men naturally take more muscle than women. The average man has 72lbs (33kg) of brawn, compared with a measly 46lbs (21kg) in women. This is partly just considering men are taller and heavier overall, but that isn't the whole story – as a percentage of overall body mass, men are nigh 38% musculus while women are 31%. This comes down to hormones: men have more 'anabolic' hormones running through their veins, which tell the torso when to abound more muscle.

Men tend to have a higher percentage of muscle mass than women because of their hormones (Credit: BBC/Getty)

Men tend to accept a higher percentage of muscle mass than women because of their hormones (Credit: BBC/Getty)

This includes an of import but little-known steroid called DHEA. It'south secreted by the adrenal glands – cocktail sausage-sized organs which sit down higher up each kidney – and is involved in everything from keeping bones strong to maintaining our immune systems.

The hormone used to exist extremely popular with athletes, partly because of its extraordinary muscle-building power, and partly because doping with it was legal until adequately recently. Simply in case you lot were getting any ideas, it as well has many drawbacks, such as the tendency to crusade liver impairment and shrink a man'due south testicles.

Just women produce anabolic hormones likewise – and the team found that those on the pill had much lower levels of DHEA in their claret.

When they worked out, women on a certain type of pill had less of the muscle-building hormone DHEA – and less muscle gain – than those not on the pill (Credit: BBC/Getty)

When they worked out, women on a sure type of pill had less of the musculus-building hormone DHEA – and less muscle gain – than those non on the pill (Credit: BBC/Getty)

Fifty-fifty more intriguingly, the poor musculus gains weren't found in all women on the pill, simply those that contained a sure type of lab-made progesterone that likes to bind to the same protein.

"Nosotros're pretty confident the progesterone is what's causing this," says Riechman. I possibility is that past competing for the same binding sites, the hormone may be blocking signals to grow more than muscle. The results haven't definitively proven the link, merely if information technology does turn out to be real, surely women volition desire to know about it – especially in the light of recent fitness obsessions such as CrossFit and Instagramming your abs. "This study should admittedly exist followed upward. People are interested and we go calls fairly regularly almost it," he says.

Fat storage

And the pill may exist changing women's bodies in other ways, likewise. Just as it has an impact on the proportion of musculus in our bodies, it could exist exerting subtle influences on fat – particularly where it is stored in the body.

At puberty, oestrogen and progesterone are responsible for the development of typically 'female' characteristics, such as wider hips and larger breasts, largely by changing the mode fat is distributed. The hormones are also oft given to transsexuals for the aforementioned reason.

The womanly 'hourglass figure' emerges as different kinds of fat tissue answer differently to these reproductive hormones. For instance, subcutaneous fatty – the kind of chub that women carry around their thighs, hips and breasts – contains lots of oestrogen receptors.

Because hormones react differently with each type of fat tissue, changing a woman's hormone balance could alter where her fat is stored (Credit: BBC/Getty)

Because hormones react differently with each type of fatty tissue, irresolute a woman's hormone residue could alter where her fat is stored (Credit: BBC/Getty)

It's easy to see how, theoretically, irresolute a adult female's hormone balance could change where her fat is stored. Some research has borne this out: ane early report found that women on pills with higher levels of oestrogen tended to have pear-shaped bodies and more subcutaneous fatty, though not necessarily more than fat overall.

Jail cell swell

Finally, there'south the superlative menace of many women on the pill: bloating.

That disgusting, swollen feeling happens because oestrogen also affects the mode the body metabolises water, past influencing the production of certain proteins in the kidneys. The cease outcome is that the body retains more fluid than it commonly would. This then seeps into fatty cells, causing them to nifty up. Considering women tend to shop more than fat in their breasts, hips and thighs, these areas tin can expand the almost.

Oestrogen can cause the body to retain more fluid, including the type used in the contraceptive pill (Credit: BBC/Getty)

This also happens on a smaller calibration in women who aren't on the pill, during the week just before their catamenia. But it'south exaggerated by the contraceptive because synthetic oestrogen is six to ten times more stiff than the natural kind, and because it'due south taken nearly every day, which means the levels of both hormones are more abiding.

So while the pill may non be leading to long-term weight gain, some women could still find that their dress fit differently.

Fluid retention may also help to explain why some women report that the pill increases their cup size. In that location accept been very few studies into the event – understandably, nigh research tends to focus on breast cancer rather than size – but back in the 1990s a couple of Swedish scientists decided to take a look.

The contraceptive pill is known to increment a woman's risk of developing chest cancer slightly, both while she's taking it and in the 10 years afterwards. The researchers wanted to know whether this might be because these women have larger breasts; there'due south an inherent risk in having (or growing) more cells, which is one reason alpine people tend to be more susceptible to cancer.

To detect out, the team tracked the monthly cycles of 65 healthy women who either were on the pill, used to accept it, or had never taken it. They found that not only did pill users take significantly larger breasts overall, simply they were especially large at sure times of the month. Women who had previously been on the pill had an average-sized bust.

One study found that the pill appears to increase breast size, and not just from water retention (Credit: BBC/Getty)

One study found that the pill appears to increase breast size, and not merely from water retention (Credit: BBC/Getty)

The squad didn't check the women'due south breast measurements before they started taking the pill, so it could be argued that these women had always had larger breasts. However, it seems likely this was due to the contraceptive pill, because their breast sizes weren't linked to the normal factors you'd wait – such as their top, BMI, or torso weight – as in the women who weren't on the pill.

Exactly how this happens remains a mystery. The breast expansion could simply exist swelling from fluid retention, only another possibility is that the hormones in the pill are actually causing women's breasts to grow. For example, the outburst of growth that happens each month, and is necessary to maintain a constant size, could be lasting a bit longer. This would lead to more tissue overall – and explain the heightened cancer risk.

Of course, whatsoever subtle effects the pill has on your figure – for better or for worse – millions of women feel that it's worth it. Equally i Reddit user put information technology, no nascence control at all is likely to lead to 25 to 35 pounds (11-15kg) of weight gain over the course of 9 months.

This story is part of the Wellness Gap, a special series virtually how men and women experience the medical system – and their own wellness – in starkly different ways.

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