“My son is gaining a lot of weight. Could it be some hormonal imbalance?”

Weight gain without obvious extra calories or decrease in activity could be a sign of several hormone problems. Most common might be an underactive thyroid (hypothyroidism) and the most common cause is an autoimmune attack on the thyroid gland itself so that less main T4 and T3 hormone is produced and TSH, the controller from the pituitary gland is elevated. Often with an enlarged goiter but sometimes only a small enlargement so somewhat subtle. Testing for two thyroid antibodies as well as total and free T4 as well as TSH should be done to check this out. There also can be other sometimes subtle symptoms such as cold intolerance, constipation of less frequent bowel movements, tiredness/lethargy and changes in menstrual function in girls/women. Other hormone problems such as adrenal gland excess (or taking corticosteroids) can cause weight gain as can hypopituitary, hypothalamic problems with growth hormone or other hormones. Important to review with your GP or PCP and then usually would need physical exam and especially some hormone levels (like the 3 thyroid levels previously mentioned above). Other tests for cortisol, ACTH, GH, IGF-1 and perhaps testosterone, LH and FSH or estradiol with LH or FSH if teenagers. A blood count, chemistry profile and lipids might also be needed and maybe also a screening labs such as sedimentation rate or CRP for inflammation markers. Stuart Brink, MD Senior Endocrinologist, New England Diabetes & Endocrinology Center (NEDEC) c/o NEDEC, 196 Pleasant Street, Newton Centre MA 02459-1815, USA phone 1-781-572-4533, e-mail: stuartbrink@gmail.com

Obesity is a medical condition were excess fat is stored in the body (in adipose tissue). Obesity is becoming a major health problem not only in the USA but also globally. In the United States over 50% of adults and over 25% of children are obese/overweight. Obesity increases risk factors such as type 2 diabetes, hypertension, fatty liver disease, sleep apnea, cardiovascular and colorectal diseases, irregular menstrual cycle and more other medical problems.
excess fat is stored in the body deep in side the body (viscera) or superficial (subcutaneous). It may be distributed in two forms. Central or Android (apple shape) or Gynoid (pear shape) obesity. Central obesity (apple shape) is when fat is deposited on the abdomen, trunk and neck. This form of obesity is common in men. Abdominal girth is much bigger in central or Android obesity. It is also true that abdominal (central) obesity is worse than the gynoid (pear shape) obesity because it exports insulin resistance, leading to metabolic syndrome, type 2 diabetes, high blood pressure, fatty liver disease, hyperlipidemia, sleep apnea and others. The Gynoid (pear shape) obesity is when fat is distributed in the hip and thigh area. This type of obesity (Gynoid) is more common in women though some men will have it as well. The gynoid obesity is not as strong as the Android obesity in causing obesity related morbidities such as insulin resistance (metabolic syndrome) as the abdominal girth is not increased to the degree of the Android obesity.
The majority of obesity whether it is Android or Gynoid are caused by lack of regular physical activity, wrong diet and excess calorie ingestion. Few cases of obesity are as a result of hormonal imbalances and genetic abnormalities. Some of the hormone causes of over weight can be thyroid hormone deficiency, excess cortisol, insulin resistance, leptin abnormalities etcetera. Obesity (overweight) due to hormonal imbalances will follow the Android or central obesity form of body fat distribution. In cortisol excess for example, the fat distribution is more prominent on the trunk and neck. There are also rare genetic abnormalities that can cause obesity. These are beyond the scope of our discussion at this time.
The human history has been so successful that we have evolved into a complex and affluent modern society. From the days of scarcity ( hunter and Gatherer) we have evolved into a wealthy society with plenty of food and endless festivities. during the days of food scarcity in the era of hunter and gatherer society a thrifty gene evolved for our survival. The thrifty gene helped as gain more weight during plenty (hunting season) and we used the body fat to survive during scarcity when there was little prey to hunt. The thrifty gene was able to store more fat by creating insulin resistance during the seasons of plenty. Those calories were used during the time of scarcity. The thrifty gene was therefore a survival gene in that era. The people who had the thrifty gene faired better than the people with out the thrifty gene. AS we became affluent the thrifty gene was no longer needed, and instead it be became a liability. It continued to unleash the epidemics of obesity leading to the metabolic syndrome mostly through insulin resistance.
Suppose we all go to the Kalahari desert to become hunter and gatherers or we go to some poor countries where there is food scarcity, regardless of the thrifty gene our body fat will melt in a matter of time. It is therefore important to appreciate that wrong diet (high carbohydrate and high saturated fat), excess calorie intake and lack of daily regular exercise are driving most of our obesity and its co-morbidities. It is therefore important to remember that nutrition is the whole mark of the maximum expression of the gene. The more food we have the more maladaptive genes will express leading to more medical problems.
Going back to your question, your son most likely gaining excess due to wrong diet (high carbohydrate, high saturated fat) excess calorie ingestion and lack of daily regular physical activity like the majority of over weight and obese people in the USA, though there could be a slim possibility of hormonal imbalance. It is therefore very important that you see your son's doctor for proper evaluation. You should ask him to run some tests to rule out hormonal imbalances and check for any genetic conditions. If his weight gain is due to hormone problems, things will improve with correcting the hormone imbalance.
The most important issue is to recognize that wrong diet, excess calorie intake and lack of regular (daily) physical activity are the overwhelming causes of the overweight/obesity epidemics in the USA. So I encourage you to look in to this issue. Healthy balanced diet with bigger portions of vegetables and regular daily structured physical activity should be intensified to maintain an ideal body weight. You should see a good nutritionist to give you a nutritional guide. Provide your son with healthy diet, limit calorie intake with out restricting growth and daily structured physical activity. Create partnership with a good nutritionist and your doctor and you as the leader of the team. If he still continues to gain more weight despite all endeavors, ask your doctor for appetite suppressing medications.
Discuss these issues with you doctor and listen to his expert advice and work as a team.
Good luck

Yes. Check for thyroid hormone.

Yes, he needs to be seen by a pediatric endocrinologist.