The body pushes back
When you lose weight, hunger hormones change: leptin falls and ghrelin rises, so you feel hungrier, and the body burns slightly less energy than expected. This is why regaining weight is so common, and why a long-term plan matters more than a quick diet.
What else plays a part
- Genes, which strongly influence body weight
- Short or poor sleep, shift work and stress
- Medicines such as steroids, insulin, some diabetes tablets, some antidepressants, antipsychotics and anti-epileptic drugs
- Life stages such as pregnancy and menopause
Is it my hormones?
Most people with obesity do not have a single hormonal cause, but some conditions do add weight and are worth checking for:
- An underactive thyroid, which usually causes modest weight gain along with tiredness and feeling cold
- PCOS, with irregular periods, acne or excess hair
- Cushing syndrome (too much cortisol), which is rare: purple stretch marks, easy bruising, muscle weakness and a round face
- Insulin resistance, often with a dark velvety skin patch on the neck
What works
- A realistic goal: losing 5% to 10% of body weight improves blood sugar, blood pressure and fatty liver
- Meals built around vegetables, protein and fibre, with fewer sugary drinks and refined snacks
- Regular activity, including strength training
- Better sleep
- Medically supervised treatment: anti-obesity medicines for selected people, and bariatric surgery for those who meet criteria (thresholds are lower for Asian populations)
When to see a specialist
Consider an endocrinology opinion if you are gaining weight despite real effort, have diabetes, PCOS or fatty liver, take medicines that may add weight, or have features of a hormone problem.
This guide is general information and is not a substitute for a consultation.