Difficult to do in an online relationship.

Excellent for real life. But I would suggest an alternative approach. Use the flogging as a reward for weight loss. Also, one ounce (and only one) dark chocolate per pound lost, an oral orgasm per five pounds.

The problem with using punishment for failure is that when it comes to weight loss, it's been shown that it really takes group encouragement and group support. Gaining weight is psychically punishing enough as it is.