The transition from childhood to adulthood — called puberty — can be awkward, and uncomfortable, but it is a part of normal human development. Puberty occurs between age 8 to 13 in boys and age 10 to 15 in girls. Since each person is unique, one person may go through puberty much sooner than another, so what's "normal" may differ. It is normal for both boys and girls to gain weight during puberty as the body is experiencing hormonal changes, which can cause excess fat to develop.
When asked about changes during puberty, Dr. Scott Cohen of Beverly Hills Pediatrics says, "Adolescence and puberty is a phase of development where you have a massive growth, both physically and emotionally, and it correlates with boys and girls having an increase in hormones in their body."
Normal Weight Gain During Puberty
It is normal for both boys and girls to gain some weight during puberty. In girls particularly, they develop what is more commonly known as "baby fat," which is actually normal adipose tissue that starts out in the belly area, and then spreads out through the hips and breasts as maturation progresses. In boys, weight gain is normal, but it takes on a more muscular form as their shoulders become wider, and they develop more muscle mass overall.
Nutrition Needed During Puberty
To assist in its development, the body requires certain nutrients to support it in doing its job during puberty to develop children into mature adults. Good nutrition and a balanced diet are required. The main change during this period is an increase of calories needed to support the growth process. It is important that these calories do not come from processed or fast foods, rather from nutrient-dense foods. Calcium and iron are especially important, as calcium helps build strong bones, and iron helps replenish nutrients lost during menstruation.
The Effect of Hormones on Weight Gain
The presence of excess fat and weight gain in an adolescent's body is due to a hormone called a GnRH (gonadotropin-releasing hormone) released by the brain signaling the body to mature. Once this hormone is released into the pituitary gland, located below the brain, it forms two new hormones called LH (luteinizing hormone), and FSH (follicle stimulating hormone). These puberty hormones signal to the body that it is time to evolve, and weight gain is needed for a woman to become fertile and for a man to gain muscle.
When to Be Aware of Excess Weight Gain
More calories are necessary during puberty, but it is still important to be aware of not consuming more than the calories needed to do the job of maturing, or an excess of weight gain will occur. This can be a sensitive time for adolescents as they may feel "fat," but dieting is not encouraged during this time, as some weight gain is normal and necessary to the process of puberty. If weight gain goes above the 85th percentile on your child's next doctor's visit, it can be cause for alarm, and a reduction in calories or types of calories may be necessary to ensure a healthy weight is maintained.