The Role of Hormones on Weight

Hormones are chemical messenger secreted into the blood and transported to their site of action to exert their effect. The release of hormones is often associated with external stimuli. Hormonal, and neural stimuli do affect hormone secretion. Furthermore, physiological factors like sleep, stress, exercise and food intake may affect the release of some hormones. 

In this article, we will review the influence hormones have on weight. 

Hormones that lead to weight gain;
i. Insulin

Insulin is highest immediately after a meal. It rises due to increased blood sugar levels. It is important in facilitating glucose uptake by cells for energy and storage. The primary energy storage form of glucose is glycogen. However, this has a limitation, the muscle and liver capacity to store glycogen runs out quickly. The next available option is storage as fat. With increased carb-diet, more fat stores are created. Further, excess sugar would lead to insulin resistance that would lead to high blood sugar levels hence Type II Diabetes Mellitus. 

ii. Ghrelin

This is the hunger hormone; it is secreted by the pancreas and stomach. It stimulates cravings and promotes weight gain as hunger leads to increased caloric intake. Activities that help keep ghrelin in-check are proper sleep and intermittent fasting.

iii. Cortisol

This hormone is commonly known as the “Stress Hormone”. It is a steroid hormone released by the adrenal medulla that when chronically elevated, leads to weight gain. Stress leads to muscle breakdown and slowed bone building and increased blood sugar.  Chronic stress halts fat burning. Sleep, exercise and meditation (among other stress relieving activities) may help reduce cortisol. 

iv. Hypothyroidism (condition)

The thyroid hormone is produced from the thyroid gland. The role of the thyroid hormone includes; 

a.    Increased metabolic rate

b.    Regulate body weight

c.    Build muscle

d.    Strengthen bone

These are the core functions of thyroid hormone. In hypothyroidism, that is, less thyroid hormone production, weight gain occurs due to reduced metabolic rate. 

Hormones that lead to weight loss
i.  Leptin


Leptin is the opposite of ghrelin. It is the satiety/fullness hormone. It is produced from fat tissue and promotes the feeling of fullness. This stops food/caloric intake and prevents overeating. After eating, leptin signals the hypothalamus prompting the feeling of fullness. However, unregulated eating can lead to leptin resistance, where leptin does not cause the feeling of fullness anymore.  

ii.       Testosterone

This is a steroidal hormone and is the predominant hormone in males and is present in women as well. It helps bone and muscle growth. It also increases fat-burning. In obesity, testosterone is significantly reduced due to reduction of sex hormone binding globulin (SHBG) that is required for testosterone transport in the body. 

iii.      Hyperthyroidism (condition)

Converse to hypothyroidism, hyperthyroidism increases weight loss due to increased metabolic activity related to increased levels of thyroid hormone. 

Key Takeaway Points

Lifestyle significantly affects hormones that influence weight. These include but are not limited to; stress, diet, exercise and sleep. 

Balancing hormones is very important to ensuring that weight is maintained fairly equal without excess loss and no gain. 

Processed foods can lead to this hormonal imbalance. High carb (sugar) diet can lead to insulin and leptin resistance as well. Therefore, high fat, high protein diet and low carb diet are recommended for better hormonal balance. 

Why Do I Lose Weight When I Start Working Out?

It is common for people to experience weight loss when they begin an exercise routine. There are several factors that can contribute to this weight loss, including burning calories through physical activity, increasing muscle mass, and making healthier dietary choices.