Loss of appetite but gaining weight

Body weight can rise from fluid retention, constipation, hormonal changes, or reduced activity even when hunger is low. A person may also eat calorie-dense snacks or drink more than they realise because meals feel unappealing. Medicines, depression, and conditions affecting the thyroid, liver, kidneys, or heart can alter appetite and weight. Swelling of the ankles, breathlessness, cold intolerance, bowel changes, thirst, or changes in urination provide useful context. Appetite loss with weight gain does not point to one diagnosis.

Record your appetite, meals, drinks, bowel pattern, activity, medicines, and weight trend without trying to crash-diet. Notice whether rings, shoes, or clothing become tight and whether swelling changes during the day. Choose regular balanced meals, limit very salty packaged foods if swelling is present, and stay active within your ability. Do not stop prescribed medicines or use weight-loss products without clinical advice.

Arrange a medical review if the change is unexplained, continues, or comes with swelling, breathlessness, marked tiredness, persistent nausea, abdominal enlargement, or reduced urination. Seek urgent help for severe breathing difficulty, chest pain, confusion, fainting, sudden widespread swelling, or inability to keep fluids down. A clinician may review medicines, examine for fluid retention, and decide whether blood or urine tests are appropriate.

Could any of my medicines or a fluid change explain the weight gain? Should I be checked for thyroid, liver, kidney, or heart problems? What weight or swelling changes should prompt urgent contact?