According to every scrap of research, the likelihood that someone’s subclinical or even frank hypothyroidism is the source of their excess weight is quite low, while the probability that their excess weight has had profound effects on both the anatomy of the gland and the physiology of the HPT is much higher. So rather than a reflexive assumption that someone who presents with weight gain or ongoing unhealthy weight should have their thyroid checked to see if that is the cause – the TFTs absolutely should be performed but instead to understand one of the key consequences of this excess adiposity. In this recording we highlight the 4 stages of impact, moving from: the ‘Overfed’ to the ‘Under-Resourced’, the ‘Disturbed’ and finally the ‘Diseased Thyroid’. The reversal of this relationship – adiposity as the cause not the consequence of thyroid dysfunction – changes everything, from what we tell our patients, to what effective management, and success, in terms of follow-up TFT patterns, actually looks like. We need to be alert and responsive to the most common and contemporary thyroid disruptor in our patients: fat is a goitrogen.