There are conflicting data about the impact of BBS variants on energy expenditure; one study reports that adults with BBS and overweight/obesity have a similar resting metabolic rate – measured using indirect calorimetry – to individuals with overweight/obesity and without BBS, with slightly lower levels of physical activity observed in individuals with obesity with BBS compared with controls.32 The gene discussed is BBS2; the disease is obesity due to melanocortin 4 receptor deficiency.