It absolutely can lead to taller people if the genetic height potential had been suppressed by poor childhood nutrition. You see this in stark form in developing countries where heights are rising rapidly (sometimes nearly a foot in one generation in individual cases). It's not only nutrition - it's access to more modern medicine, including vaccines and treatments, and improved sanitation that prevent childhood diseases that stunted people in the past.

If a population is already on average at its maximum genetic height potential, however, improved nutrition and healthcare isn't going to change height much.