Causes of weight loss

Weight gain - and the difficulty of losing it - comes from an energy imbalance, but the reasons behind that imbalance are layered: habits, hormones, medicines and modern life all push in the same direction.

The core equation, honestly stated. Weight rises when energy in (food and drink) exceeds energy out (resting metabolism plus activity) over months and years. The surplus needed is surprisingly small - even 100-200 extra calories a day becomes kilos over years. What drives the surplus is where the real causes live.

The everyday drivers: large portions of calorie-dense food (fried items, sweets, maida products, sugary tea and soft drinks, packaged snacks), grazing through the day, and sedentary living - desk work, screens, vehicles for short trips. Poor sleep (under 6-7 hours) directly increases hunger hormones and next-day eating. Chronic stress drives comfort eating and abdominal fat through cortisol. Alcohol adds empty calories and appetite.

Medical contributors worth checking. Hypothyroidism, PCOS in women, Cushing's syndrome and insulin resistance can make gain easier and loss harder. If weight gain is rapid, unexplained, or comes with fatigue, irregular periods or other symptoms, a doctor should test - treating the condition changes the weight equation.

Medicines that promote gain: steroids, some antidepressants and antipsychotics, some diabetes medicines, and certain anti-epileptics. Never stop them on your own - ask the prescriber about alternatives or counter-measures.

Genes and age: genetic tendency is real but acts through appetite and metabolism, not fate - lifestyle still decides most of the outcome. Metabolism slows modestly with age and muscle loss, so the same eating that kept you stable at 25 gains weight at 45.