Patient's appearance is sufficient to arrive at a diagnosis in most cases. Obesity is determined based on an individual's body mass index (calculated with reference to the person's height and weight).

The following are the most common symptoms that indicate an adolescent is obese. However, the patient's appearance is sufficient to arrive at a diagnosis in most cases, determined by the persons BMI (body mass index) depending on weight to height, though each adolescent may experience symptoms differently. Symptoms may include:-

Large body frame.

Difficulty in doing daily activities. 

Lethargy 

Breathlessness

Disproportionate facial features

Breast region adiposity - (sagging fat cells) in boys

Big belly (abdomen), sometimes marked with white or purple blemishes

Male external genitalia may appear disproportionately small

Early arrival of puberty

Flabby fat in the upper arms and thighs

Knock-knees (Genu valgum) is common

The symptoms of obesity may resemble other medical problems or conditions. Psychological disturbances are also very common as well as stress, social pressure and doing developmental chores. Always consult your adolescent's doctor for a diagnosis.