I'm wondering if this is referring to NPH. When I was on NPH (first 13 years of diabetes) I originally took two shots a day, one R + NPH at breakfast and one R + NPH at dinner. Then about 9 years into diabetes I switched to an adult endocrinologist and he suggested moving my NPH shot to bedtime to avoid overnight peaks and valleys. So then I was on three shots a day: R + NPH at breakfast, R at dinner, and NPH at bedtime. (For a while my endocrinologist tried eliminating R at dinnertime if my BG was normal, but that was quickly dropped!)
Of course, to most people on NPH I would definitely recommend moving to a more updated regimen such as MDI or the pump. But some people are happy only taking two or three shots a day. In some ways, diabetes was much more simple back then; but, of course, decent control depended on a ridiculously strict schedule, and even then was near impossible to achieve.