If you're only a few pounds overweight, losing those pounds isn't going to make a difference in your height. The exercise you put in to do it, though, might. The improved posture gained from regular, functional exercise can make you look noticeably taller. That said, the entire game changes if you're clinically obese -- in which case, yes, losing a significant amount of your body weight can leave you standing a little taller in more ways than one.
Science Says ...
The best scientific evidence of height gains after losing weight comes from a study conducted by Israeli neurosurgeon Zvi Lidar and colleagues. Published in 2012, the study was intended to document changes in intervertebral disc height after weight reduction in morbidly obese patients. The researchers noted that "disc height restoration after weight reduction was significant." They noted an increase of about 2 mm in just one intervertebral disc, between the fourth and fifth lumbar vertebrae.
Even if you don't lose enough weight to gain a few millimeters of height back, even a modest weight loss can provide significant health benefits. A weight loss of 5 to 10 percent is enough to give yourself the gift of better control over your blood sugar, reduced blood pressure and reduced cholesterol levels. Research indicates that you may even increase your longevity, too -- so in a real sense, losing weight can mean taking back a part of your life.