Children will be allowed into the Museum's Science of Sport exhibition for free if they bring along an Easter egg on Tuesday 13th April - the day after an Easter weekend of gorging on chocolate.
The amnesty - which is supported by the British Dietetic Association and Sport England - is designed to offer young people the chance to learn about the importance of balancing diet and exercise.
Children will be able to try running on a treadmill while wearing a specially designed 'fat pack' or measure their fat levels using a body mass indicator.
Paediatric dietitian Justine Sharpe, who will be leading the day of workshops for the British Dietetic Association, says:
"This is a great way of encouraging children to learn about the relationship between activity and diet.
"It is crucial that children understand it is important to lead an active lifestyle and maintain a balanced diet - the two are not mutually exclusive."
Instead of the normal £6.95 entry charge, Easter eggs will be handed over as payment to a 'sporting bunny' who will look after them while children are inside the exhibition burning off calories and learning about the importance
of a balanced diet. They will be offered their Easter egg back after they have been into the exhibition.
The Top Speed IMAX film was produced by the same team that produced the critically-accailmed Everest IMAX film.
Top Speed features the downhilling - on a bobsleigh run - of MTBer Marla Streb, who has clocked 67mph on a mountain bike.
In 2000, she won bronze at the MTB World Championships and also posed nude - atop her bike - for US magazine Outside.
She lives in America and likes going fast on two-wheels:
"I think defying nature makes us feel special. Prehistorically speaking, our bodies weren't designed to go more than about 20 mph, even during a full sprint. Now, by striving for top speeds, we're surpassing even evolution. Fear should never be an issue while racing a mountain bike because it only slows you down. If I'm ever afraid of a section on the race course, I approach that part thinking scientifically about the pure physics of the event, with no emotion.
"I use my science background to structure my training and organize my approach to racing. Sometimes, science also helps me to twist legitimate theories around in order to rationalize some crazy jump or risk, like knowing that the gyroscopic motion of my turning wheels will stabilize me, but only with increasing speed, or that spacetime is relative the faster that you travel!
"In the near future a critical mass of kids who are just beginning to ride their bikes now going to school, in the woods, just messing around -- will make sure mountain bikes go much faster than the world champions could ever dream of today."