Yes, it's completely normal to look "fatter" or curvier during puberty, especially for girls, as hormonal changes cause fat to redistribute to hips, breasts, and thighs, while boys gain muscle and broader shoulders; this weight gain and body shape shift are essential parts of healthy development, with bodies often looking "out of proportion" until growth is complete.
Body shape – Another sign of puberty in girls is changing body shape, particularly extra fat in the belly area (some call it “baby fat”). Weight gain can cause anxiety for girls. This is part of normal development, and her body will redistribute the fat from the stomach and waist to the breast and hips.
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.
Teens can have a high BMI if they have a large frame or a lot of muscle, not excess fat. And a person with a small frame may have a normal BMI but still can have too much body fat. Also, it's common for teens to gain weight quickly — and see their BMI go up — during puberty.
Because you are a normal teenager. Everyone has (at some point or another) stomachs that sticks out. This is either from bloating, a large meal, or a bit of extra cushioning. Having a completely flat stomach 24/7 is not natural, even for the most petite individuals. Remember to treat your body with kindness.
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.
Eat a healthy diet, watch portion sizes, and exercise regularly. In addition to cardio activities like running or biking, exercises like crunches and planks, which don't require a gym, can help you tone up your stomach and core muscles.
70kg (about 154 lbs) can be a healthy weight, but it depends heavily on your height, body composition, and overall health, as it falls within the normal Body Mass Index (BMI) range for many people but could be overweight for shorter individuals or underweight for very tall ones. For instance, a person 1.75m (5'9") tall with 70kg has a normal BMI, but height is key, so consulting BMI charts or a doctor is best for a personalized assessment.
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.
West Virginia topped WalletHub's 2025 ranking of the most overweight and obese states in the U.S., published Nov. 4, while Colorado is the healthiest-weight state.
Adolescence is a time when girls will gain more fat tissue and add fat stores on their thighs, breasts, and hips. In boys, the weight gain is mostly from muscle gain. Knowing that these body changes will happen can help reassure children that they are growing as they should.
“It's normal for a child to slim down between ages 2 and 5,” says pediatrician Roy Kim, MD. “Your child will look their thinnest about the time they start kindergarten.”
As youth are growing taller, it's normal to gain weight. Rising amounts of estrogen in the body also cause fat to deposit in the hips and breasts, and the overall percentage of body fat increases in girls as they go through puberty.
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.
One reason for belly fat is a sedentary lifestyle. Even skinny people can spend too much time in front of the television or computer screen, and this can encourage what little extra fat they have to settle into the stomach. A diet high in processed foods can also cause belly fat, even in skinny people.
The signs of puberty include:
A single night of no sleep will not stunt growth. But over the long term, a person's growth may be affected by not getting enough sleep. That's because growth hormone is normally released during sleep. If someone consistently gets too little sleep (known as "sleep deprivation"), growth hormone is suppressed.
Childhood obesity is a serious health condition that involves having excess body fat early in life. The extra weight often starts children on the path to other health conditions such as diabetes and high blood pressure. Childhood obesity also can lead to poor self-esteem and depression.
In adults, overweight, or pre-obesity, is defined as a BMI of 25-29.9 kg/m², while a BMI ≥ 30 kg/m² defines obesity.
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)
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.
Think eating plan, not diet.
In general, a low-carb way of eating shifts your intake away from problem foods—those high in carbs and sugar and without much fiber, like bread, bagels and sodas—and toward high-fiber or high-protein choices, like vegetables, beans and healthy meats.
Puberty - Increased hormones in a child's body during puberty (between the ages of 10 and 14 for girls and between the ages of 12 and 16 for boys) leads to growth and possible expansion of “baby fat” areas. This typically takes place in girls' belly, breast area and hips.