What causes obesity?
There is a myriad of multiple factors influencing the progression towards obesity:

1. Life-style

   • Sedentary​ lifestyle and exercise

     • Your body will constantly burn calories ​despite being sedentary. In order for your body to maintain normal bodily processes, there is a required minimum daily energy expenditure. If you do nothing the whole day your body will still use up minimum calories as energy and that is called basal metabolic rate or the minimum daily calorie requirement. By exercising you will be utilizing more calories as fuel, leading to a calorie deficit that causes excess fat to be taken up as energy.
        

   • Diet

     • Atkin's diet or ketogenic diet which comprises of high fats and low carbohydrate diet causes a depletion of sugars in the body. The body then starts using fats as a replacement of sugars to acquire energy and burns the fat as a source of calorie. This diet may not be the best option and there are many studies that have debunked the safety and health benefits of the ketogenic diet.

     • Your diet should comprise of all nutrients but in Atkin's diet, there is a disproportionate amount of fat to protein and carbohydrate percentage which may be less healthy.

     • The Malaysian ministry of health has advocated for the diet plan called "suku-suku-separuh". In our language, it means a "quarter-quarter-half". This indicates the ratio of an entire plate comprising of a quarter of protein, a quarter of carbohydrates, and half of fiber. This is a simple way to quantify the ideal ratio of the nutrients but it is not necessarily effective for everyone. This plan lacks specificity to each individual with different problems
       
       
        

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2. Psychological diseases

   • Stress​ or depression
     ​With the changes in the current busy and taxing world, stress higher than it has ever been. Humans are creatures of habit and we are more comfortable in conditions where we are doing something repetitively while reaping their rewards immediately. For example scrolling through Twitter, Instagram, or watching Youtube videos. The reason scrolling through these social media platforms is so addictive is because of the repetitive motion of scrolling and get immediate satisfaction. Immediate satisfaction nullifies the feeling of depression or stress.
     
     People manage stress by overeating because the act of picking up food and putting it into the mouth is considered a repetitive action that can be therapeutic. Eating causes people to feel good about themselves because eating activates the immediate reward system of the brain therefore reduces stress. 
     
      

3. Metabolic syndrome

   • Diabetes​
     Diabetes is a chronic disease. In diabetes, the body is unable to utilize sugar in the body well. The sugar floats in the bloodstream and the cells cannot capture the sugar to be used by the cells to function well. This tricks the cells of the body to tell itself that it is lacking sugar but in reality, the body has excess sugar in the bloodstream.
      
     Therefore the body hungers for more sugar because it because and results in the person having more to eat. The excess sugar accumulates more and more until the body uses sugar and becomes fats. This process of changing excess sugar into fats is called lipogenesis.
     
     Lipogenesis is mostly derived from carbohydrates and is a relatively minor contributor to whole-body lipid stores, contributing 1–3% of the total fat balance in humans consuming a typical diet. Lipogenesis increases considerably when individuals are fed a hypercaloric high-carbohydrate diet and are stored as adipose tissue or in the liver.
     
      

   • Dyslipidemia
     Some people are at higher risk of having poor fat metabolism and more in obese children. Obese is translated as high cholesterol or/and triglycerides. Genetically some population of people stores fats easily as compared to other people. Situations like Primary or Familial dyslipidemia is an inherited disease caused by a single genetic mutation in one of several genes. Genetic abnormalities that lead to abnormal blood lipids are most often found in genes involved in the transportation and cellular uptake of lipids. 
     
      

   • Gout
     Studies have shown that being overweight causes insulin resistance which hampers the kidneys in carrying out their duties. This then reduces uric acid excretion which, in turn, leads to high blood uric acid. Not only that, fat cells themselves contain proteins called leptins which can also affect the kidneys’ ability to excrete uric acid.
     Obesity is closely linked to gout; as the country’s obesity rate has gone up, so has its rate of gout. 
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
      

4. Hormonal status​

   • Menopause
     The hormonal changes of menopause might make you more likely to gain weight around your abdomen than around your hips and thighs. Obesity is a multifactorial issue which means that hormonal changes alone don't necessarily cause menopause weight gain. Instead, weight gain is also related to aging, as well as lifestyle and genetic factors.
      

   • Andropause
     Andropause is a condition similar to women having menopause but it affects the male hormones in the male body. We know testosterone has multiple functions to regulate muscle mass, boost energy, concentration, libido, and psychological well-being.
     Low testosterone does not mean that the testosterone is below the normal value, rather the testosterone is close to the lower limit of the normal range.
     
     Low testosterone causes muscle mass loss, tiredness, poor libido, loss of concentration, and andropause depression.
     Overtly high testosterone causes muscle mass gain, good libido, hyperactivity of mental function and aggression,
     Therefore, it is important to hit a sweet point for the testosterone to be normal but on the high normal levels.
      

   • Cushing's Disease
     This is a chronic situation where is excessive cortisol and this causes weight gain.  The excess cortisol in the body does not increase protein and carbohydrate metabolism. It slows or nearly disables metabolism function, which can cause weight gain (fat accumulation) in the buttocks, abdomen, cheeks, neck, or upper back. This rare disease also causes loss of muscle mass.
      

   • Hypothyroidism
     Low thyroid hormone causes weight gain because the person's metabolism drops significantly with low thyroid hormones. People tend to gain weight with low thyroid and it can be a factor causing obesity.
      

5. Drug-induced

   • Antidepressants ​

   • Sulfonylurea 

   • Insulin

   • Anti-histamine

   • Steroid

   • Contraception pills
     
     These medications may increase appetite and change certain processes in fat and sugar metabolism. Weight gain can surely be linked with certain medications but you will have to explore these situations with your doctor.
      

6. Socio-economical

   • Many studies have been conducted in multiple countries, showing that socio-economical circumstances affect the rates of obesity. Each country has many inconsistent findings related to socio-economical status causing obesity. It has also been proven that there is some correlation between socio-economical status leading to obesity and diabetes.