Do Antibiotics Make You Gain Weight?

do-antibiotics-make-you-gain-weightEvery parent knows the value of antibiotics. They’re among the last lines of you or your child’s defense when infection strikes. And while antibiotics are meant to do good, they can also backfire when used too much too often.

Something that has recently popped up is the question, “do antibiotics make you gain weight?”

Weight gain and antibiotics may not sound like they’re related. However, they actually might be since these drugs affect the bacteria colonies living within our bodies. And as much as there are bad bacteria that make us sick, there are also good bacteria that promote health.

Antibiotics however, don’t discriminate. They do their jobs by wiping out all bacteria, good or bad.


Too Much Antibiotics Too Often

The bigger problem though isn’t really the antibiotics themselves, because as we all know, antibiotics aren’t meant to be used unless they’re really necessary.

However, parent and many physicians are prescribing antibiotics more often than before.

This does help shorten the recovery time and quickens the elimination of the bacteria. But it also comes with some side effects.

Adults and kids today are prescribed these drugs much more often than they were a decade ago.


Infections and Antibiotics

antibiotic-medicationInfections and antibiotics go hand in hand.

When an infection develops as a result of some harmful microorganisms that have infiltrated our immune systems.

These microorganisms, which were either already present in our body before but were just dormant, or usually just having entered our bodies from the external environment, cause us to get sick.

To better understand it, here are few examples. Common symptoms infections include sore throat, diarrhea, cough and fever.

To combat these infections, antibiotics have been developed and are currently used. The word antibiotic has its roots from the word anti which means ‘against’, and bio meaning ‘life’.

This does not mean however, at all that antibiotics are against life. Instead, they fight against the harmful microorganisms, namely bacteria, which are the root cause of the infection. That way, you’re not just treating the symptom, say cough with cough syrup, but dealing with what’s causing the cough, which could be a respiratory infection.


Side Effects of Antibiotics

As with most medication however, the intake of antibiotics has its side effects.

Over use of antibiotics can make certain infectious microorganisms resistant. This means that using the same antibiotics for that illness may not work next time. This is how superbugs, or infections that don’t have any antibiotic that can get rid of them, come about.

Common side effects reported from the use of various antibiotics include heartburn, diarrhea, fungal infections, nausea, bloating and vomiting to name a few.

Because of their side effects, these drugs are often prescribed by physicians later on the treatment, unless there are no other drugs that can be used.


Do Antibiotics Make You Gain Weight?

A more recent discovery that has been highly discussed is the side effect of antibiotics that cause people to gain weight.

In fact, according to research published in the International Journal of Obesity stated that kids who were put on a course of antibiotics in the recent past experienced short term weight gain.

In addition, the study also learned that the cumulative amount of antibiotics one has taken has an effect of their weight later on. This was a direct correlation, which means the more antibiotics you’ve taken over the course of your lifetime, the more the weight gain as you age.

The study compared kids who had taken antibiotics with those who hadn’t. And comparatively, kids who take antibiotics were associated with gaining weight faster than those who didn’t take antibiotics.


Why Do Antibiotics Cause Weight Gain?

weight-gainIt is important to keep in mind that our body has good bacteria as well bad.

These good bacteria help in our digestion and absorption of nutrients. They are also present to help boost our immune system.

To say that antibiotics only work to kill off bad bacteria is taking a limited view of the broader picture.

When we take an antibiotic, the drug it disturbs our body’s inner ecology. It destroys certain types of bacteria colonies, including those that promote health.

Each antibiotic tablet is also associated with the increase of the hunger hormone ghrelin. Ghrelin works by regulating our hunger pangs. And when we have high levels of this hormone, it sends signals that make us want to eat more. In addition, we also end up storing more excess fat.

Aside from ghrelin, these drugs also affect the satiety hormone leptin. In combination with ghrelin, leptin work together, like stop and go signals as far as feeling hungry and full go.

With antibiotics in our systems, our bodies may stop responding to the signal, ‘You are full and you do not need more food.’ So, we end up eating and eating, which results in weight gain.


Antibiotics and Nutrient Absorption

Antibiotics also affect our intestinal bacteria. These colonies are involved in the absorption of nutrients from food. They also work to regulate insulin sensitivity and reduces inflammation.

Damage to these bacteria disturb our body’s healthy metabolism process. And when this happens, it may result in weight gain.

Antibiotics can also damage cell mitochondria as well, which are substances present in our cells that convert food into energy. The connection is then easier to make, no conversion, more absorption of fat, more weight.


Antibiotics Being Used in Our Food Sources

Another interesting way antibiotics are leading to weight gain is through our intake of farm-bred meats. Farmers have found that antibiotics can help their animals to grow fatter. This should already give you a hint of what these drugs to humans as well.

Hence, instead of using healthier food for their breed, they tend to resort antibiotics to their animals. It’s a quick and sure way to get higher prices when they go to market. This ultimately mean that the meat we buy or eat in restaurants is rich in fat, not leaner. Thus resulting in weight gain.



With the amounts of side effects antibiotics have, it is being considered that even a single course per year can be too much.

This is the reason that your doctor does not prescribe antibiotics straight away when they diagnose you with some infection.

It is better to build on your immune system with healthy diet and nutritional supplements so that the harmful bacteria does not affect your system.


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