Hormones are chemical messengers that regulate the processes in our body. They are one of the factors of obesity. The hormones leptin and insulin, the sex hormones and the growth hormone influence our appetite, our metabolism (the rate at which our body burns kilojoules of energy) and the distribution of body fat. Obese people have levels of these hormones that promote abnormal metabolism and the accumulation of body fat. A system of glands, known as the endocrine system, secretes hormones into our bloodstream. The endocrine system works with the nervous system and the immune system to help our body cope with different events and stresses. Hormonal excesses or deficits can lead to obesity and, on the other hand, obesity can lead to hormonal changes.
Which Hormone Imbalances Trigger Weight Gain?
Leptin is mainly secreted by fat cells (adipocytes). It regulates energy expenditure, appetite and food intake. Your lifestyle and diet play a key role in regulating leptin levels and your body weight. A study in rats found that consuming fast, processed foods, sugary drinks, and too much fructose can lead to leptin resistance and, therefore, obesity. As you continue to eat more foods that contain fructose, more fat builds up and more leptin is secreted. In turn, this desensitizes your body to leptin and your brain stops receiving the signal to stop eating. This ultimately leads to weight gain.
It should be noted that low and high levels of estrogen can lead to weight gain. Overproduction of estrogen through ovarian calls or consumption of foods rich in estrogen can lead to high levels of estrogen. A healthy body produces the desired amount of insulin and controls blood sugar. However, high levels of estrogen in the body stress the cells that produce insulin. This makes our body resistant to insulin and leads to high levels of glucose, which in turn leads to weight gain. Mostly, lower levels of estrogen are found in the elderly when there is less production of estrogen hormones. To produce more estrogen levels, the body extracts fat cells and converts all energy into fat to recharge glucose levels. This is another reason for weight gain.
This gland is positioned at the base of your neck. It is responsible for the production of T3, T4 and calcitonin, which maintain the body’s metabolism. If these hormones are underproduced, it can lead to hypothyroidism, associated with weight gain. You can prevent it by consuming iodized salt, taking vitamin D, eating well-cooked foods, and consuming foods rich in zinc.
Insulin is secreted by the pancreas and is responsible for transporting glucose to cells. It is used as energy or stored as fat, which in turn maintains blood sugar. When there is an interruption in insulin levels, the body becomes resistant to insulin. Muscle cells therefore do not recognize insulin linked to glucose and glucose remains in the bloodstream. Consequently, it causes an increase in the blood sugar level and leads to weight gain. To avoid this situation, you should eat seasonal fruits and vegetables, flax seeds, avoid alcohol and late-night snacks.
Melatonin is a hormone secreted by the pineal gland. It regulates the circadian rhythm, that is to say the rhythm of sleep and getting up. Melatonin levels in the body tend to increase from evening to late at night and to ebb early in the morning. Poor sleep quality lowers the melatonin level, which results in reduced physical activity, induces stress, and stimulates the production of cortisol (a stress hormone). This increases glucose metabolism and lowers the level of adiponectin (a protein hormone that promotes fat breakdown), which leads to weight gain. Low melatonin levels and poor sleep quality increase calorie intake at night, which is again linked to weight gain and increased BMI.
There is evidence to suggest that long-term behaviour changes, such as healthy eating and regular exercise, can re-train the body to shed excess body fat and keep it off. Studies have also shown that weight loss as a result of healthy diet and exercise or bariatric surgery leads to improved insulin resistance, decreased inflammation and beneficial modulation of obesity hormones. Weight loss is also associated with a decreased risk of developing heart disease, stroke, type II diabetes and some cancers.