I only go number 2 every 4 days or so. does this allow my body to absorb more calories from the foods i eat?

No: But it does suggest that you need more fiber, fluid & physical activity to get your bowels moving a bit more frequently. With that said, as long as you're not straining to pass a bowel movement, then you're probably normal as stool frequency varies greatly. To be on the safe side, if you're also overweight, lethargic & intolerant of cold, consider asking your doc to check your thyroid function.