In the context of this study, inflammation of the hypothalamus can lead to various diseases, including metabolic syndrome and cardiovascular disease. Metabolic syndrome in particular is interesting because it's a cluster of symptoms that includes high blood sugar and obesity. It's long been known that low-carb/ketogenic diets are an effective treatment for it.
You wouldn't actually feel hypothalamic inflammation. You'd eventually just get fat and ill.
"These signaling functions suggest that BHB might itself regulate inflammation and gene expression, with implications for health and longevity. Aberrant inflammasome activity is associated with a variety of age-related diseases (Goldberg and Dixit, 2015), while moderate inhibition of histone deacetylases is associated with enhanced longevity in invertebrates (Woods and Rogina, 2016) as well as amelioration of cognitive decline (Penney and Tsai, 2014) and cardiac dysfunction (Morales et al., 2016) in mice."
You wouldn't actually feel hypothalamic inflammation. You'd eventually just get fat and ill.