For the poor individuals who are genetically inclined to become obese.
Nine out of ten times the problem is not inherited, it is taught.
I have so often witnessed parents (at restaurants) tell their children to eat up, otherwise they will not be given sweets afterwards. Poor kids, they are already stuffed to the gills, they are forced to eat whatever is on their plates and afterwards they forcefeed themselves with sweets in order to get some joy from the meal.
Two hours later, they feel nauseous and have to be given medication to stop the nausea. It only postpones the inevitable – what should have been an afternoon barf becomes a two-o-clock-in-the-morning session, bedding full of something resembling a pizza that ended up in the dishwasher.
Poor kid gets whacked for eating too many sweets and stinking up the entire house with barfodour – the sticky smell with the same retention qualities in the atmosphere as in the poor individuals mouth.
You can brush your teeth ten times afterwards and gargle mouthwash for two hours and you will still end up with a mouth that tastes like mouthwash-tootpaste-barf.(MTB)
These lessons in overeating are well remembered and the forcefeed/barf sessions become ingrained. Some develop eating disorders i.e. eat too much and barf to prevent nutrition from reaching the posterior and thighs. (Called Bilumia?) It should be called EATANDBARFIMIA.
The other eighty percent end up with a gullet the size of a kit-bag ala navy SEAL type with the ability to retain vast amounts of food without becoming nauseous (being whacked every time they dared to barf from just after birth).
These poor kids end up resembling their parents (profile wise) and everybody assumes that it must be genetic.
As the centuries pass it becomes genetic eventually. The progeny will strive to protect themselves from EATUPABUSE by developing the ability to eat a lot without becoming nauseous.
Eatandbarfimia has a tendency to cause all sorts of problems like malnutrition and social aversion, maybe from the individuals breath always resembling MTB.