Loss of appetite and weight gain: what to know

Body weight reflects more than how much you want to eat. Fluid retention, constipation, reduced movement, medication effects and hormonal or metabolic changes can increase weight even when meals are smaller. Stress or low mood may alter routine, sleep and activity, while some people eat calorie-dense snacks despite little interest in full meals. A scale change can therefore have several explanations.

Consider whether the change was sudden or gradual and whether rings, shoes or clothing feel tighter. Note swelling, breathlessness, bowel changes, thirst, urination, sleep, mood and every medicine or supplement. A clinician can interpret the pattern with your medical history.

Keep meals regular and modest rather than skipping food for long periods. Choose nourishing foods you tolerate, include fibre if appropriate, and drink normally unless a clinician has given you a fluid restriction. Gentle movement can support digestion and routine when you feel well enough.

Weigh under similar conditions if monitoring is useful, but avoid repeated checking that increases worry. Do not begin a restrictive diet, diuretic or weight-loss product without professional advice, especially if swelling or poor intake is present.

Arrange an appointment for unexplained or continuing weight gain with reduced appetite, particularly with swelling, breathlessness, abdominal enlargement, persistent constipation, marked tiredness or changes in thirst and urination. Seek urgent help for sudden breathlessness, chest pain, fainting, confusion, severe abdominal pain, or rapidly increasing swelling.

Ask whether fluid retention, constipation, a medicine, mood, activity or another health issue could explain the pattern, and whether your weight and nutrition need monitoring.