It's normal for teens to gain weight and body fat during puberty for growth, but being overweight (obese) can increase health risks like type 2 diabetes, high blood pressure, joint pain, breathing issues, and fatty liver disease; it can also affect pubertal timing and future health, so while some weight gain is expected, managing excess weight with healthy lifestyle changes (diet, activity, sleep) is important, ideally with a doctor's guidance, as this period sets patterns for adulthood.
Noticeable weight gain may occur prior to a growth spurt as excess fat helps promote growth. As a child goes through puberty, their stores of body fat may change. For example, girls tend to gain more fatty tissue in the hips, thighs and buttocks, while boys may have an increase in fat on their stomachs.
Obesity can affect your teen's health in a number of ways. These include: High blood pressure and high cholesterol. These are risk factors for heart disease.
Studies have shown that excess weight and obesity affect the start of puberty differently for boys and girls. In girls, it can cause early puberty and in boys it can delay puberty.
Pediatric obesity has various long-term consequences, including endocrine alterations and musculoskeletal conditions (1), which contribute to an altered growth pattern. Prepubertal children with obesity are generally taller than their peers, but grow more slowly during puberty (2, 3).
Obese children are usually taller for their age but also fatter and mature faster, but they do not tend to attain taller height as adults since excess adiposity during early childhood has an influence on the process of growth and puberty.
Another common cause of delayed puberty in girls is lack of body fat. Being too thin can disrupt the normal process of puberty. This can occur in girls who: Are very active in sports, such as swimmers, runners, or dancers.
As kids begin puberty, dramatic physical and emotional changes take place. Kids gain about 20 percent of their final adult weight, bone mass increases by about 40 percent, organs grow bigger and the brain undergoes significant changes.
Obesity rates among Gen Z in the U.S. as of 2024
Using data from UnitedHealth Group and the Health Action Council, the rate of obesity among Gen Z females was estimated to be nine percent. In comparison, around five percent of Gen Z males were thought to be obese.
The 3-3-3 rule for weight loss is a simple, habit-based method focusing on three key areas: 3 balanced meals a day, 3 bottles (or ~1.5L) of water by 3 PM, and 3 hours of physical activity per week, aiming for consistency over complex diets. It simplifies fat loss by establishing rhythm through consistent eating, adequate hydration to support metabolism, and regular movement, promoting sustainable health without intense calorie counting or restrictive rules, says Five Diamond Fitness and Wellness, Joon Medical Wellness & Aesthetics, and EatingWell.
Obesity is a serious, chronic disease. It can lead to other health problems, including diabetes, heart disease, and some cancers. Obesity is becoming much more common in childhood. Most often, it begins between the ages of 5 and 6 years and in adolescence.
Researchers have found that the number of fat cells in your body is set during adolescence and remains constant through adulthood, regardless of whether you gain or lose weight.
Gaining weight during adolescence is totally normal and very important! It is a natural part of the growth process. Until about 20 years old, children's weight is meant to increase. From birth, through childhood and through the teen years your child's weight is never meant to be less than it was the day before.
A big belly in a normal child
The reason is that the structure of the intestines in children is longer than the size of the abdomen. In addition, the abdominal wall muscles are not fully developed, so children often have a tense belly, which is a normal physiological phenomenon.
Although adequate nutrition is essential for normal growth and children with obesity are usually taller than their normal-weight peers, they do not tend to attain taller height as adults [25].
Changing Body Shape
Boys tend to look a little chubby and gangly (long arms and legs compared to the trunk) just prior to and at the onset of puberty. They start to experience a growth spurt as they progress further into puberty, with the peak occurring during the later stages of sexual maturation.
Getting slimmer is not an automatic part of puberty. It does happen to some, but for most people, losing weight during puberty takes as much work and will power as losing weight at other times.
Studies have consistently shown a clear association between childhood overweight and obesity and the early onset of puberty in girls. A growing number of longitudinal studies confirm that overweight or obese girls enter puberty earlier than their normal-weight counterparts, a trend observed globally.
According to the Centers for Disease Control and Prevention (CDC), most 13-year-old females weigh around 76 to 158 pounds (lb), and most 13-year-old males weigh between 75 and 158 lb , but this can vary widely. The CDC has set guidelines for healthy weight and body mass index (BMI) in children.
Unlike overweight girls, who tend to reach puberty earlier than do girls of normal weight, overweight and obese boys in the U.S. may begin puberty later than thinner boys.
The most common method of measuring obesity is the Body Mass Index (BMI). BMI = Person's weight (kg) / Person's height (in metres)². In adults, a BMI of 25kg/m² to 29.9kg/m² means that person is considered to be overweight, a BMI of 30kg/m² or higher means that person is considered to be obese.
Sleep deprivation has long been linked to an increased risk of becoming overweight or obese. Researchers found that getting less than seven hours of sleep resulted in weight changes and may lead to weight gain, either by increasing food intake or decreasing energy burned.
If you're too thin or underweight, you may experience complications such as: Weakness or lack of lean muscle tissue. Low energy. Sub-optimal bone health (osteoporosis)