In a 1-cup measuring cup, add 1 Tablespoon of fresh lemon juice. Top the lemon juice with skim, low fat or whole milk. Stir and let sit for two minutes. After two minutes, your milk is both acidic and curdled. If you need 2 cups of buttermilk, add 1 tablespoon plus 1 teaspoon of lemon juice or vinegar to the milk.
Larger broken bones, for example the bones in the thigh, or both bones of leg would take a great deal longer to heal, usually six weeks to three months in the average healthy adult. Begin physical therapy as soon as is practical. That will help.
Prepare yourself for boredom from lack of exercise for 6-12 weeks. Healing a foot stress fracture is not a quick process by any means. It is one of the longer recovery periods because we have to use our feet at some point. The longer you can stay off your feet and let it heal, the quicker the healing will take.