I’ve suggested (in conversation) that every boy should be ‘clipped’ at birth. Then you have to meet a number of social parameters/criteria (job, education, somewhere to live, etc.) for the sterilisation to be reversed and then to be given the chance to produce offsping. That should remove the wheat.
Not actually my opinion, but just an opinion.
As for culling obese people, my BMI is presently 29.9kg/m2. When I was playing rugby (and considerably leaner than I am now) it was ~33. I’m glad Trimix never came to watch me play. Sniper in the grandstand anyone?