Slang for diabetes. The reason is that oftentimes people with severe Type 2 diabetes are obese and have a high sugar intake level. One's feet are highly susceptible to damage from Type 2 diabetes due to the sugar intake, and sometimes the tissues in their feet dies and it needs to be removed.
"Doctor said that if I don't stop eating deep-fried twinkies for breakfast I'm gonna get sugarfoot and he's gonna saw off my leg!"
Sugarfoot is a term for a sweetheart. A kind soul, who is a solid female friend and always has your back. When apart (in prison, across states/countries, down the street) she is the one you think of and its good feelings all over. You know, the kind that are all warm and fuzzy.
Also, the kind of girl that will put money on your books and/or send you care packages to show you she cares and you are not forgotten.