There is an element of truth in the overused excused, "I have glandular problems". Although most cannot blame their weight problems completely on their hormones, hormones do affect weight. To some degree, hormones are responsible for weight gain or loss. A person's diet, lifestyle and activity level influence the body's hormones in positive or negative ways.
Lifestyle and Hormones
The majority of the hormones involved with weight loss are produced in response to stimuli. Lifestyle habits such as exercise, eating patterns and stress levels all have a role to play in the production or non-production of specific hormones that help to keep a person fit.
Endorphins - Endorphins are the cause of the euphoria that comes from exercising intensely over a long duration. Because of that euphoric feeling, the exerciser is able to push on for longer periods of time. When a person exercises regularly, the body becomes more sensitive to these hormones. As a result, the endorphins stay in the blood for even longer after a workout is finished.
Epinephrine -- While a person exercises, this hormone stimulates glycogen release and helps break down fat in the muscles and liver. The amount increases with longer and more intense exercise.
Human Growth Hormone (HGH) - The right amount of HGH causes the body to use less glucose and more fat for fuel. Over time, the more a person exercises, the more HGH the pituitary gland produces.
According to Mayo clinic, when a person is deficient in HGH, injections of this hormone have been shown to decrease body fat as well as increase muscle mass and exercise endurance. Healthy adults have seen improvements in muscle mass and decreased body fat with HGH injections. However, the increase in muscle does not translate into an increase in strength (Reference 3).
Insulin - Insulin is responsible for the regulation of blood glucose levels. It directs glucose, fatty acids and amino acids into the cells of the body. Eating several smaller meals throughout the day gives insulin a reason not to overwhelm the body's cells with sugar and a regular habit of exercise keeps insulin blood levels low.
Thyroxine - Produced by the thyroid gland, this hormone increases the rate of metabolism in every cell of the body. Too much thyroxine can cause hyperthyroidism which leads to rapid weight loss. Too little thyroxine is termed "hypothyroidism" which leads to rapid weight gain due to the slowing down of metabolism. When a person's thyroid gland is functioning normally, there is an increase in thyroxine levels over the length and intensity of an exercise routine.
Cortisol - Cortisol is called the "stress hormone" because the levels increase with stress. Too much cortisol causes insulin resistance and too much insulin can create more cortisol. Belly fat is the most common symptom of weight gain due to an overproduction of cortisol. The natural treatment for high cortisol levels includes stress management techniques such as relaxation, exercise, getting enough sleep and eating a well balanced diet.
Barring hormonal imbalances due to heredity or disease, the hormones responsible for weight gain and loss can be controlled by proper diet and exercise.