Why Do People Become Overweight or Obese? by nutritionist Laiba Imran
Gaining extra weight usually happens slowly over time. The main reason is simple: when we eat more calories than our body needs, the extra is stored as fat. This is what we call an energy imbalance.
Our body uses food for two main purposes:
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Fuel for now – to help us breathe, move, think, and do daily activities.
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Fuel for later – stored as glycogen (from sugars) in the liver and muscles, and as fat (triglycerides) in fat tissue.
When we keep taking in more than we burn, the “storage tank” fills up, leading to overweight and eventually obesity. But it’s not just about eating too much — many other things like sleep, stress, medical issues, or even where you live play a role too.
What Increases the Risk?
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Not moving enough
Sitting for long hours at work, in front of the TV, or on the phone makes it easy to gain weight. Adults need around 150 minutes of exercise a week (like brisk walking, cycling, or swimming), and kids need at least an hour a day. -
Unhealthy eating habits
Eating more calories than your body can burn.
Diets high in fried foods, processed snacks, sugary drinks, or desserts.
Too much saturated fat (like from fast food or butter).
Too much added sugar (like sodas, candies, or sweetened coffee/tea).
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Poor sleep
If you sleep less than 7 hours most nights, your hunger hormones get out of balance. This can make you feel hungrier and crave more junk food. -
Stress
Stress raises the hormone cortisol, which can make your body store more fat and increase cravings for high-calorie foods. -
Health conditions
Issues like PCOS (polycystic ovary syndrome) or metabolic syndrome can make it harder to control weight. -
Family history and genetics
Some people naturally gain weight more easily because of their genes. But lifestyle choices — eating better, being active, managing sleep and stress — still make a big difference. -
Medications
Certain medicines can lead to weight gain, such as:
Antidepressants
Antipsychotics
Some blood pressure medicines (beta-blockers)
Birth control pills
Steroids (glucocorticoids)
Insulin for diabetes
If this happens, talk to your doctor about alternatives.
Your environment
Where you live matters. It’s easier to stay healthy if you have parks, sidewalks, and grocery stores nearby. But if your neighborhood has mostly fast food outlets and no safe spaces to walk or play, it’s harder to make healthy choices.