A strict diet for a seal in Gweek is going to be a tough challenge for one of his keepers also.

Male grey seal Yule Log has ballooned by 124 kilos in nine months, to 346 kilos – close to the maximum for the species.

At his latest weigh-in at the Cornish Seal Sanctuary staff gasped at the reading, while one of them, animal care assistant Jenny Lewis, tried to make herself scarce.

Her colleagues know that Jenny has a soft-spot for 24-year-old Yule Log, so knew instantly who was to blame for the old boy’s expanding girth.

Jenny, a 29-year-old zoology graduate, confessed: “He’s such a lovable character I haven’t been able to resist giving him the odd extras at feeding time.”

In fact Jenny was not just giving Yule Log extra helpings at the seal feed, she was also treating him to anything left over from penguin and sea lion feeds.

Her bosses were not too hard on her though. They have all learned that Yule Log’s pleas for extras are difficult to resist.

Supervisor Tamara Cooper said: “If he doesn’t think he’s getting his fair share he swats the water with a giant flipper and drenches whoever is holding the fish bucket.

“We’re all in for a few soakings in the coming months as we try to get Yule Log back in trim, but Jenny will be getting the most.”

Jenny has convinced her colleagues she can be trusted, but there will be regular monthly weigh-ins to ensure Yule Log does indeed shed the kilos and gets back to a healthier size.

“The target is to get him back below 300 kilos,” said Jenny, “and then not to ease up on his new regime to make sure he stays there.”

She knows it’s going to be tough and has admitted she will feel quite sad every time she passes the seal pool and is followed by Yule Log’s big pleading eyes.

She is also prepared to get a lot of use out of her waterproofs in the months ahead.

Ten free annual passes for Gweek Seal Sanctuary are up for grabs. See advertisement ihn this week's Packet.