If you have an insatiable appetite, it may be down to a protein-coding gene called brain-derived neurotrophic factor (BDNF) which is produced by bone marrow cells and affects the regulation of food intake.
Scientists have been researching this gene looking for ways to help utilise this knowledge in the fight against obesity, diabetes and metabolic syndrome. Unfortunately for overeaters, so far bone marrow transplants which do not contain BDNF have failed to reverse overeating, obesity or insulin resistance.
There is good news for under-eaters and those needing to gain weight though! If you are born lacking the ability to produce blood cells which make BDNF, it may be possible in the future to restore the gene for making blood cells which DO produce BDNF that can normalise appetite and lead to healthy weight gain.
Urabe H, Kojima H, Chan L, Terashima T, Ogawa N, Katagi M, Fujino K, Kumagai A, Kawai H, Asakawa A, Inui A, Yasuda H, Eguchi Y, Oka K, Maegawa H, Kashiwagi A, Kimura H, Haematopoietic Cells Produce BDNF and Regulate Appetite upon Migration to the Hypothalamus, Nature Communications, 2013, 4: 1526.