Lukaku arrived at San Siro from Manchester United this summer in a deal worth €80 million (£74m/$90m), after enduring mixed fortunes during his two seasons at Old Trafford.
He was immediately given the No. 9 shirt formerly belonging to ex-Inter captain Mauro Icardi, whose stand-off with the Nerazzurri has continued throughout pre-season amid reports he will soon be leaving the club.
Little more than a week prior to the start of the Serie A campaign, however, Lukaku found himself under the media microscope.
Influential sports daily Corriere dello Sport claimed that the Belgian was tipping the scales at 104kg, above the 100kg limit tolerated by the Inter medical staff, and thus may be unavailable for the season opener against Lecce.
Those criticisms prompted the player to take to Instagram to prove that he is in fact in fighting-fit shape.
"Not bad for a fat boy," he wrote on the publication of a black and white mirror selfie designed to contradict his critics.
Corriere are not the only ones who have focused on Lukaku's physique in recent weeks.
"I think Lukaku is a goalscorer and he will score plenty of goals, but the way they want to play at times, he’s too heavy," Pallister said in a recent interview.
"You look at the pace in the present game; maybe Ole is looking at that and saying he can’t implement that into his game for me. He was surplus to requirements.
"He’s a goal scorer, an instinctive goal scorer. He’s not the most clinical but he will get you 15-20 goals a season, but we were looking for a more rounded player."
Lukaku joined United from Everton in the summer of 2017 and racked up 96 appearances in all competitions, scoring 42 goals at a rate just shy of one every two games.
His official Inter career begins at home to Lecce on August 26 - providing he makes the cut at the weigh-in.