I know the answer now, but my guess before watching was 138kg. (I guessed170kg until I watched him and his mate lift it - then I revised my estimate

To reduce the temptation to cheat, the prize is a kiss on the cheek from Beany. You may choose any of your 4 cheeks, but the kiss must be collected from wherever Beany is at the time, and you may have to indulge him with up to 4 minutes of “chase me” before it’s delivered.
Note: if Beany himself wins, he’ll get to kiss an A4 (colour) image of IanF’s left buttock. (Usual price £4.00, or £7.20 for two kisses).