Is Obesity Genetic Feature Image

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Obesity is one of the biggest growing global health problems with an estimated 1.9 billion adults, 18 years and older being overweight with 650 million of these people are classed as obese. Most of the world’s population live in countries where overweight and obesity kills more people than underweight.

It is now a global epidemic and has started to receive huge amounts of press coverage throughout mainstream and independent media, however, most media outlets don’t seem to be focusing on the root cause of obesity, instead, they focus on how you may be able to tackle the problem by promoting fancy diet products and celebrity weight loss plans.

The real crux of the issue is what actually causes obesity? Is it genetic as some people claim, or is it behavioral?

You may have heard people say “I’m big boned” or “it’s hereditary”, attributing their genetics to the root cause of them being overweight and not really investigating their behavior.

There’s no doubt that there are some aspects of your genetics that play a role in how much you weigh, how well your body can process fats, and how efficient your body is at burning excess calories, and even water retention which can make up a percentage of being overweight. The problem with this is unless you have an actual abnormal genetic condition that can account for extra weight gain, then it’s mostly down to behavioral traits.

Can You Really Be “Big Boned”?

There’s no such thing as being “big boned”, you can certainly have different sized bones to the person sat next to you, however, they are usually in proportion to your height and overall figure. Bones are bones and they are the same in every human being on the planet.

You may have slightly different proportions in relation to your overall body, but you can’t have extra bone weight that accounts for being obese and we prove that because you will never see an x-ray of an overweight skeleton.

Can My Genetics Make Me Fat?

There is one super rare condition called, ‘monogenetic obesity’ which appears to be the mutation of certain genes that are responsible for your appetite and food intake. Very little is known about this and it’s thought to be very rare.

As far as a specific gene of a genetic condition that just makes people gain weight, science has not found any evidence of this. There are however other aspects of your physiology that can play a part in your weight control.

There are some conditions that can cause you to gain weight and you may not be aware that you’re suffering from the condition, especially if it’s in the early stages.

Hypothyroidism Causing Weight Gain

This is a condition where the thyroid gland, located in the neck, produces too little thyroid hormone. Thyroid hormone regulates our metabolism so if you are not producing enough of this hormone it can slow your slow your metabolism and often causes weight gain. You would need to undergo a blood test to confirm this.

Depression Causing Weight Gain

While depression isn’t necessarily built into your genetics, it can alter levels of serotonin which is a monoamine neurotransmitter responsible for feelings of well-being and happiness. Many people overeat when they are suffering from depression so this could well be a medical cause for being overweight.

Can My Behavior Make Me Fat?

YES! This is the most widely accepted reason for most people being overweight and becoming obese, your behavior, or more specifically, your eating habits. Many people simply fall into a trap of not cooking proper meals and turning to snacks throughout the day or ready meals that are packed full of saturated fat, sugar, and processed meats.

Now, you could have very valid reasons for this such as long office hours, always looking after the kids, or you might just never get a minute to cook real food, however, this is all down to behavior that can be adapted if you really try to find the time.

You also need to look at your actually eating habits. Do you really need to have that last chocolate bar before bed? How many times have you told yourself you’ll have a healthy breakfast tomorrow and then stopped off at the bakery on the way to work or picked up a load of snacks?

You may not notice but you will certainly have eating habits that are the main contributing factor to your weight gain. An eating habit can even include meeting up with friends every weekend and choosing high-calorie alcohol over meeting up for coffee or tea.

Does Stress Make You Fat?

How many times have you reached for junk food when you get home from a long day at the office? Stress can contribute to your behavioral eating habits and can take some time to change but if you don’t start then you’ll never control that habit.

Do Fat Genetics Run In The Family?

No, fat genetics do not run in the family but bad eating habits certainly do. If your parents fed you junk food as a kid then there’s a good chance your brain is wired to crave the very same foods throughout your adult life.


Are you destined to be fat? Unless you have an actual genetic condition, no you are not. For sure, there are certain aspects of your biology that means your metabolism is slower, or even faster than the person sat next to you, however, these variations are almost never usually so drastic that they can cause one person to just become overweight.

If you have a condition such as hyperthyroidism then yes, this can cause you to gain weight, and some psychological conditions can also cause you to overeat, but unless you have an actual genetic abnormality, then being fat is not just stored in your genetics.

Your eating and behavioral habits are the main cause of gaining weight, being overweight or even being obese. If you really take the time to look at what you’re eating and why you’ll quickly find that it’s usually your lifestyle and food choices that are making you overweight.

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Fact Checked

This article has been reviewed and fact-checked by a certified nutritionist, and only uses information from credible academic sources.