From Kevin Boyd Is it not interesting that obesity, and its associated comorbidities, are associated with a higher lifetime prevalence of all-cause dementia? However, is it obesity that is a causal factor or the fact that obesity is strongly associated with (1) reduced exercise and a sedentary lifestyle, (2) hypertension and metabolic syndrome (insulin resistance), (3) systemic inflammatory syndrome, (4) mental health problems (depression/anxiety) and (5) sleep apnoea and other sleep disorders? All five of these factors may be the causal factor and not necessarily obesity itself. The modern epidemic of obesity is been driven largely by a change in our diets in particularly the ubiquitous consumption of processed and ultra-processed foods and the large increase in sugar (sucrose) consumption. Prior to the Victorian era, sugar was not a dietary staple and we tended to eat large quantities of unprocessed foods. Eating unprocessed foods meant we had to work hard at chewing food, which crea...