Revealing mistake: In the scene where the king and his entourage are walking through the crowd, someone in the crowd (right side) is wearing a watch on his left hand while applauding.
Revealing mistake: In Episode 2 during the scene when the king's son is born, it appears that the baby has been born for less than a few minutes, but when he is held up it is plain to see that his navel has healed instead of being freshly cut As It Should Be after the birth. (00:31:50)
Revealing mistake: The king arrives to see his first son. As the king gets off his horse and is greeted by a foot solider, you can see modern grey fencing behind him with green shrubbery growing around it.
Revealing mistake: In the scene where the King's sister is throwing things at Charles in rage, she says "don't call me wife" and hurls a goblet at him and it hits the window behind him. A sound of breaking glass is heard, yet you can see the plastic 'window' flap and the 'glass' stays in tact. (00:38:50)
Answer: While he was obese for much of his life, Henry VIII didn't gain significant weight until after the death of Jane Seymour when he fell into a deep depression and succumbed to the pain of a leg injury he obtained from a jousting accident. He should've been heavier but he wasn't obese for his whole life, especially during his younger years. He was known to be 210 pounds, standing at 6'2", and to have a 32" inch waist for much of his life.