Puberty can be a scary time for both adolescents and their parents! With so much changing, it’s important to know what’s normal and what can be expected.

In my practice working with kids aged 8-15, the biggest concern parents have is adolescent weight gain: How much weight should their child be gaining, when does the weight gain start, and how should parents feed their child at this time?

Pubertal weight gain is necessary and normal

To start with, weight gain is something that happens during this time, and it’s 100% necessary! Puberty is the 2nd most rapid time of growth (second to baby’s first year), and weight gain is needed to fuel this growth.


Puberty generally occurs for girls around ages 8-13, and boys aged 9-15. Growth is very individualized and differs between each adolescent. Some children will get taller and then fill out, some may gain weight first and then get taller… either way is normal and no one should tell you otherwise.

* Important note: If your child is going up or down on their growth chart (jumping percentiles), that may be a sign that something is not right, and should be addressed by their pediatrician or a dietitian.

Boys in diverse body sizes jumping on rocks near water

How much weight will they gain over puberty?

Over the course of puberty, girls will grow around 10 inches and gain 40-50 pounds, and boys can grow 12 inches and gain 50-60 pounds. This weight gain is crucial for their development, as it allows for;

  • Bone growth and strengthening
  • Muscle growth
  • Organ growth
  • Increased fat storage to prepare a girl’s body for the (far in the future) birthing process

Basically, a lot of growth!

Because it’s individual how your child experiences puberty, it can be a difficult experience for your child, and they’ll be relying on you for support! (even though they probably won’t tell you that)

Girls in diverse body sizes sit together on a log

How can you support your child during puberty?

Normalize it!

Kids need to know that their experience is normal, and puberty is part of growing up. Though they may feel uncomfortable in their current body, let them know that it will change over time. For example, fat first accumulates in one area to start (such as around the belly), and over time it spreads out to the rest of the body.

Feed their growth

Puberty is not a time for weight loss. The weight that’s being gained is crucial for development and has long lasting effects- well into adulthood. Continue providing kids with a variety of all foods in a family setting (see benefits of having scheduled family meals and how to make them enjoyable) and providing more autonomy in making their own food choices when able.

Help them develop a neutral-positive body image

Kids generally have a high self confidence and belief in their own ability. As kids (girls especially, but boys too!) get older, they develop insecurity which is often manifested in the way they feel about their bodies. Help your adolescent develop a positive (or at least neutral) body image by focusing on their abilities and skills rather than appearance; exposing them to diverse body types; and helping them recognize that their body changes are normal. (You can read more about developing a positive body image here.) Seeing the diversity of development amongst their peers can be difficult, especially if they’re amongst the earlier or later developing kids.

Model and encourage the belief that no body type is better than others, and bodies come in all sizes, shapes, and colours.