Does being overweight affect your height?
Not much. In a large multi-center study Stovitz et al. Am J of Human Biology (2011) came to the following conclusion:
"Adjusted for age, and race/ethnicity, young adult obesity status explained a small, but statistically significant amount of height growth among both females and males within each of the three intervals. Compared with normal weight young adults, overweight or obese young adults stood taller in childhood, but had relatively less growth in height throughout the teenage years. There was no association between adult height and weight status. "
Another study by De Leonibus et al (2012) reported the same trend:
"Several studies have shown that during pre-pubertal years, obese patients present higher growth velocity and that this pre-pubertal advantage tends to gradually decrease during puberty, leading to similar final heights between obese and non-obese children. "
So, the final height does not seem to be affected; one has to be aware of other health problems linked to obesity in children and teens.