Technically this can come from Jupiter, The Sun, Venus or Pluto, or any signs related to them, plus relevant afflictions. Neptune can cause mental issues, distorted body perception and lapses that lead to this.
Overall unaspected Saturn could lead to this, I imagine, as Saturn rules restrictions.
One can do regression to see if this happened in past lives.
Obesity is a complicated issue, there are different reasons one can be prone to becoming obese. Also a lot of this deals with the group karma of negative manifestations of Jupiter spiralling out of control.
We didn't live in as 'Jupiter-enriched' times 100 years ago. The average person could not go outside and purchase 6 Krispy Kremes to scarf (or at least, we had the other negative side of Jupiter related to christianity instead and a lot of negative Saturn causing deprivation and famine, which now has been replaced with shoving donuts down one's throat).
Hence much less obesity, but people still had the same Natal Charts. Only a few people like Fatty Arbuckle or whatever were fat. Group factors must be taken into acccount.