Why did I suddenly jump in weight?

Question:

Hello,

Today I weighed myself and I was shocked that I was 131 pounds. I’m usually around 18 BMI and this is now 21.5. I am happy that I gained that weight because now clothes look normal on me but what makes me concerned is that

  • I jumped to that BMI within about 2 months or more.
  • I haven’t seen any significant height growth in a while so I’m mainly concerned that I’ve stopped growing. I feel that if I have been growing, my body wouldn’t need to store weight. I have gotten the bone age test about 2 years ago. It was about 1.5-2 years younger than my actual age but at the same time, the Tanner stage test that I just took says that I’m at stage 4.1 which means ‘growth in height has slowed down’ :(. I feel that I’ve already had a growth spurt. I know you can get more but what worries me is that both my sisters probably had one growth spurt, and stopped at 5’2 (they both stopped growing around 15), while my mom is 5’4. So what if I get stuck at 5’5.5″ while my dad is 5’7″ :(.

I know height is 60% genetics and 40% environmental so is there anything that I should that will help me continue to grow?

Is possible that my body is storing this fat for a potential growth spurt?

Answer:

What you are saying is that you went from 110 pounds to 131 pounds in two months. And I take it that your height has remained 5’5.5″. A BMI of 18 is actually underweight and 21.5 is normal weight. It is during stage 4 that you start building muscle mass, so if you have been exercising I can see that as the cause of your weight gain. What I can’t determine, since I can’t see you, is whether this gain is due to fat, water retention, or muscle. Overall, I don’t think you have anything to worry about unless this gain continues.

In regards to height, boys in your family would have final adult heights anywhere from 5’4.5″ to 6’2.5″. Where you would end up in that range depends on the genes that you inherited from your parents. Since you are at the beginning of stage 4, you can expect to gain 1 to 3 additional inches while you are in stage 4, which lasts about two years.