Insulin, produced by the pancreatic gland, helps glucose move from the bloodstream into cells, where it is required for movement, growth and repair. This explains why diabetics who do not make or use insulin can become very weak.
http://ummid.com/news/2011/November/15.11.2011/human_enzyme_n_weight_loss.htm
http://ummid.com/news/2011/November/15.11.2011/human_enzyme_n_weight_loss.htm