These are two of the most common questions I’m asked about food and skin – and the answers are not straightforward. Key to this is what is known as the glycaemic load of your diet, a measure of not just how fast a food raises your blood sugar but also how much of it you eat. Following the Mediterranean diet (which is known to be anti-inflammatory – and psoriasis is linked to inflammation) means eating broadly along the same lines as you would following a lower glycaemic load diet, including more vegetables, fruit, beans, wholegrains and fish. If you’re convinced that a specific food is fuelling your skin complaint, speak to your doctor or dermatologist before cutting anything out. It has been forming beneath the surface of your skin for weeks, so yesterday’s meal or snack isn’t the culprit.