As per The Sun, Greenwood was snapped stopping for a Burger King with his father, Andrew, after training at Getafe's base in Madrid on Friday, which could invite the wrath of head coach Jose Bordalas.
The report claims that the Getafe boss has banned all players from eating junk food and carefully monitors their weight each day. Fines are usually issued to any players reporting for club duties overweight.
Greenwood was still selected for Getafe's latest La Liga outing, which saw them play host to Real Betis on Saturday.
The game ended in a 1-1 draw as Borja Mayoral's 17th minute effort for the hosts cancelled out a shock first minute opener from Marc Roca. Greenwood played 78 minutes of the contest before being replaced by Oscar Rodriguez.
United took the decision to loan Greenwood to Getafe in the summer transfer window, after a six-month internal investigation into his conduct away from the pitch. The 22-year-old had previously been suspended by United after being arrested on suspicion of attempted rape and assault.
All charges against Greenwood were dropped in February, and he is now attempting to reignite his career in Spain. The forward has recorded one goal and one assist in his first six La Liga appearances for Getafe, who will be back in action against Mallorca on October 28.