Hormones affecting Weight Management

Updated: May 29, 2020

Obesity is almost never caused by a single factor. It is the result of a complex interplay between diet, lifestyle, our hormones - Thyroid (Metabolic hormone), Ghrelin (Hunger hormone), Leptin (Satiety hormone), Cortisol (Stress hormone), Insulin, Glucagon, Growth Hormone, Gastrin, Somatostatin, Adrenaline, Cholecystokinin, Serotonin, Dopamine (to name a few). Obesity could also be from factors that mimic or confuse our hormones (which can be found in things we eat, in the environment we live in, in our home, in the cosmetic products we use, etc. Remember that the weight management system has worked beautifully for most of us until the industrial revolution and the widespread use of chemicals not only around us but also within the very food we consume). At any given time, our body is doing its best by balancing out the various hormones to give us the best chance of staying healthy. Most of the time it works perfectly. But the balance may be skewed towards weight gain if one of the factors is present in excess or deficient states and/or for too long. To lose weight we only need correct the balance and we will start to lose weight without much effort. Weight loss is not just about diet and exercise. Our sleep (timing/duration/quality), stress, number/type/timing of meals, exposure to pollution/chemicals, etc affect how our body secretes hormones. I have briefly mentioned below some of the hormones that have an effect on weight. This list is not exhaustive. We are discovering more hormones every day. 1. LEPTIN is the satiety hormone and is produced by fat cells in our body. It is supposed to tell our brain that we have enough fat stored and do not need to eat more. It acts on the hypothalamus to reduce our craving for food. Therefore, the more fat we carry, the more leptin we should have, and the less hungry we should be. But it does not always happen this way. When the body stops responding to Leptin, it is called Leptin resistance. Research is still taking place to work out the exact mechanism of leptin resistance. Leptin also has other functions in the body: Fertility, insulin secretion and sensitivity, wound healing, inflammation in the body, immunity and brain function. 2. GHRELIN is the "hunger hormone" and is mainly produced by the stomach and is supposed to tell our brain that the stomach is empty and needs food, i.e. it creates hunger. Ghrelin acts on the hypothalamus (like Leptin). Ghrelin also acts on regions of the brain involved in reward processing such as the amygdala (hence may be involved in "comfort eating"). Ghrelin levels rise when fasting and just before eating. Dieting, therefore, will increase Ghrelin levels (i.e. increase hunger) and make it difficult to control or maintain weight loss for too long. Having a meal reduces Ghrelin levels. Interestingly, Ghrelin levels are generally lower in overweight persons. This suggests that excessive hunger is not usually the cause of weight gain - another reason why dieting may not work in the long term. Gastric bypass surgery reduces Ghrelin and therefore reduces hunger for a short time. But because Ghrelin (i.e. hunger) is not usually the cause of weight gain (read as - something else is the cause of weight gain). Patients usually put weight back on months-years after the surgery as the stomach is gradually stretched again. The reason some people are able to keep the weight off for much longer after surgery is because they have concurrently overhauled their lifestyle factors which usually addresses the underlying problem causing the weight gain. Addressing these factors before surgery would have resulted in weight loss anyway. Ghrelin also has other functions in the body: It affects the release of insulin and growth hormone, muscle and bone metabolism, reduces body heat, reduces sympathetic nerve activity (i.e. the flight or fight response). 3. THYROID Hormone is the metabolic hormone. Thyroid is a small gland located in the front of the neck. It secretes thyroid hormones T4 & T3. Every cell in the body depends upon thyroid hormones for regulation of their metabolism, i.e the way our body uses energy. The thyroid's hormones regulate important body functions including breathing, heart rate, body temperature, central and peripheral nervous systems, body weight, muscle strength, cholesterol levels, menstrual cycles, and digestion. They do so either directly and/or by regulating other hormones. Excess T3/T4 causes anxiety, shaking (tremor), moodiness, sweating, diarrhoea, missed or light periods, hair loss. Deficiency of T3/T4 causes tiredness, fatigue, difficulty concentrating (brain fog), trouble sleeping, depression, frequent heavy periods, constipation, and joint/muscle pain. The thyroid gland itself is ultimately under control of the Hypothalamus (yes, the same area that responds to Leptin and Ghrelin). 4. INSULIN is a hormone made by the pancreas that allows our body to use sugar (glucose). Sugar cannot enter most of our cells directly. After we eat food and our blood sugar level rises, the pancreas releases insulin into our bloodstream. Insulin opens the 'gates' allowing the cells to absorb sugar from the bloodstream, thereby reducing the sugar in the blood, and increasing sugar in the cells. The sugar in the cells can either be burnt off (helped by exercise or by other hormones that increase metabolism) or it may be converted into fat/cholesterol. When the body stops responding to insulin, it is called Insulin resistance and this resistance can develop with weight gain. Not all organs in the body develop resistance to the same extent. This tilts the balance in the body and we may be geared for weight gain. Addressing insulin resistance may help weight loss AND losing weight may also address insulin resistance. (Chicken or the egg predicament). However, don't lose hope. There are solutions to this. 5. CORTISOL is called the stress hormone and helps the body respond to stress or infections. It also regulates a wide range of vital processes throughout the body, including metabolism and blood sugar levels, regulation of the immune response (acting as an anti-inflammatory hormone), influence on memory, control of salt and water balance, and effect on blood pressure. Blood levels of cortisol vary through out the day, and are generally highest in the morning. Cortisol levels are ultimately dependent also on the Hypothalamus (yes, the same area in the brain again). Excess cortisol causes weight gain mainly in the face (flushed and round face), chest and abdomen, osteoporosis, skin changes (e.g. easy bruising and purple stretch marks), muscle weakness, mood swings (anxiety, depression or irritability), thirst, and high blood pressure. Deficiency of cortisol causes fatigue, dizziness (especially upon standing), weight loss, muscle weakness, mood changes and the darkening of regions of the skin 6. Some of the other hormones affecting our food, choices of food, portions sizes, feeling of fullness etc, are Glucagon, Growth Hormone, Gastrin, Somatostatin, Adrenaline, Cholecystokinin. As we can see above, hormones play an important role in regulating our weight. The functions of most hormones overlap a few of the others to some extent, and this is beneficial because it provides the body with some redundancy - i.e when one system fails, another can take over. However this can only work to a limited extent. We start to gain weight when the body cannot compensate anymore or more systems start to fail. We have seen above that Hypothalamus is an area of the brain that is crucial in the control of our energy balance and appetite. Most hormones responsible for weight gain exert their effects on hypothalamus. Because hypothalamus is part of our brain, it affects and is affected by other parts of our brain as well. Therefore psychological strategies such as Hypnosis can help in weight loss. Talk to a Clinical Hypnotherapist for advice. Not every overweight person has gained weight for the same reasons, then how can we expect the same technique to help everybody lose weight? Once we correct the 'balance' through multi-targeted approach that addresses our diet, lifestyle, medications, psychological factors that are unique to each of us, we will start to lose weight without much effort. We have to take an individualised holistic approach. An Integrative/Holistic GP can help with this.

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