Neuro Primer: Hormones and Body Weight

People all over the globe have the perception that being overweight or obese is caused by eating too much junk food, drinking sugary drinks, or not exercising enough. People with weight problems blame themselves for not being able to change their behavior in order to lose weight and get rid of the excess fat. There’s no doubt that eating too much sugar and getting too little exercise are bad habits. However, they’re not the sole cause of obesity and weight gain. In fact, there’s another reason why you may have excess weight — hormones.

The Oxford Dictionary defines hormone as “a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action”. In other words, hormones secreted by the brain carry regulatory messages to the rest of the body.

Is it possible that hormones can influence your weight? Yes: Hormonal imbalance or a misinterpretation of the signal they’re sending has a great impact on our health and weight regulation.

Leptin Hormone (Illustrated by McCall Sarrett)While every hormonal imbalance is a threat to our body, several hormones are linked to obesity and weight control problems. The first such hormone is leptin. Leptin is in charge of regulating appetite, metabolism, blood pressure, heart rate, and other bodily functions because it has hunger-blocking effects on a region of the brain called the hypothalamus. The fat cells in our body release leptin, which lets your brain know you’ve had enough to eat. Leptin is responsive to fructose, the sugar found in fruit and some processed food. People who eat too much fructose at one time can’t process it all, and the extra fructose is then converted to fat. As a consequence, too much fat creates too much leptin, and your brain becomes resistant to this hormone. Thus, you stop receiving the message that you’re full, and you overeat – leading to obesity.

Cortisol Hormone (Illustrated by McCall Sarrett)If you’ve ever been under a lot of stress, you may have felt the need to eat more food in order to feel better. This is thanks to cortisol, a hormone related to metabolism and stress management. This “stress hormone” is another reason why you sometimes have an undeniable need for food. Here’s how stress and anxiety can cause the increased production of cortisol in your body: when we’re facing a stressful situation, the adrenals secrete cortisol. Cortisol prepares the body for immediate survival, increasing the amount of glucose and storing fat because it feels threatened. This would be fine if the modern way of living didn’t include constant stress. However, with frequent stressful situations, this hormone is constantly elevated which increases your appetite leading to weight-gain. Therefore, your stress causes you to store fat instead of burning it.

Estrogen Hormone (Illustrated by McCall Sarrett)Estrogen, the female sex hormone, regulates the development and functioning of the female reproductive system and can also be responsible for weight gain (especially in menopause). Estrogen levels influence food intake, fat storage, and metabolism. Estrogen is also closely linked to another hormone — insulin. Insulin is in charge of lowering and controlling your blood sugar level. When estrogen levels are elevated, they disrupt the production of insulin, which leads to high blood sugar. Ultimately, it causes your body to store fat, leading to weight gain. An imbalance in insulin level, also known as insulin resistance, can even lead to the development of type 2 diabetes.

The thyroid gland (an endocrine gland located in the neck) and its improper functioning can also lead to excess weight. It influences your metabolism and therefore plays an important role in maintaining a healthy weight. If you experience hypothyroidism, which is when your thyroid isn’t producing enough thyroid hormone, it makes your metabolism slow down. As a result, you start storing fat instead of burning it, and you gain weight easily.

Neuroscience illuminates the impact of hormones on the brain and on our physical and mental health. We’ve learned that hormonal balance is crucial to overall health and well-being, and that an imbalance in the level of any hormone can cause numerous and serious health problems. These hormones play a significant role in maintaining a healthy weight and affecting weight gain or obesity. In fact, not only do they influence the way we feel and think about food, but they also influence the way our body processes and stores it. Hormonal imbalance may not explain all fluctuations in our body weight, but it can explain a lot of it.


Written by Daniela McVicker
Illustrated by McCall Sarrett



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Neuro Primer: Hormones and Body Weight (Illustrated by McCall Sarrett)

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Daniela McVicker

Daniela McVicker graduated from Durham University and has an MSc in cognitive neuroscience. Her passion is examining the hidden processes happening inside our brains. She works in the field of medical analysis, dealing with perception concepts, behavioral issues and neural mechanisms underlying cognition. She is also a blogger and editor at Top Writers Review. She writes to share her knowledge and experience, in order to inspire the new generations to continue researching and asking questions no one has asked before.