If just eating fewer calories and doing more sport should lead to weight loss, why do most diets fail? There is more to weight gain and loss than just calories and willpower – hormones and stress also play an important role.
A number of important hormones that affect metabolism and weight are leptin, ghrelin, insulin and cortisol. You can read below how these hormones work in the body.
Leptin: tells you when to stop eating
Leptin is a hormone that is produced by your adipose tissue and it tells your body when to stop eating. It regulates appetite and metabolism and it warns the brain when you store excess fat. There are also cases when your body stops responding to this hormone; this is called leptin resistance. Leptin resistance causes you to feel hungry and reduces the number of calories you burn. People who are obese basically have high levels of leptin, but the leptin signal isn’t working (leptin resistance).
Potential causes of leptin resistance are: inflammation, increased free fatty acids and high leptin levels. All three are elevated in obesity. Fortunately leptin resistance can be reversed, so there are a number of things you can do:
• Avoid processed foods
• Eat soluble fibre
• Ensure you get sufficient sleep
• Lower your triglycerides
• Eat proteins
Ghrelin: tells you that you are hungry
Ghrelin is a hormone produced by the stomach and it tells your body that you are hungry. Ghrelin informs the central nervous system about the nutritional status, regulates the calorie intake and fat content of the body, plays a role in regulating long-term body weight and prevents catabolism.
Ghrelin is an important factor in metabolic control during fasting: food intake reduces ghrelin levels and fasting causes ghrelin levels to rise. People who are overweight have low ghrelin levels.
There are some things you can do to help optimise your ghrelin levels:
– Maintain a stable weight
– Avoid long periods of dieting
– Eat more protein
– Get more sleep
Ideal ratio of ghrelin to leptin
The ideal situation within a good hormone balance is a low ghrelin level and a high leptin level. These two work together by saying: “I no longer feel hungry” (ghrelin) and “Stop eating” (leptin). Overweight people receive contradictory instructions due to leptin resistance: “I no longer feel hungry” (ghrelin) and “keep eating” (leptin).
Insulin: regulates blood sugar levels
Insulin is the hormone that regulates our blood sugar levels. Insulin plays an important role in our body. It provides blood glucose to cells for direct energy, it ensures the storage of blood sugar in your muscles (in the form of glycogen) and the burning of sugars as energy. When weight loss (or rather: the burning of body fat) is a goal, it becomes all the more important to consciously look at the food you eat and the production of insulin.
Glycemic Index (GI) is a measure of how quickly insulin rises after eating. If you eat foods with a high GI value, the body produces a lot of insulin, causing insulin levels to rise and the blood sugar level to drop; this disrupts and reduces the fat burning, giving you the need for sugar-rich food. The result? You feel hungry again immediately after eating. For many people, this is one of the main problems in losing weight.
A negative effect of eating many foods with a high GI value is that cells become less sensitive to insulin. The less sensitive you are to insulin, the more fat is stored. You can increase insulin sensitivity with cinnamon, chromium, gymnema sylvestre and by eating low-GI foods such as fish, vegetables, nuts and seeds. Improving insulin sensitivity ultimately results in a healthier body composition (percentage of fat).
Cortisol: helps the body deal with stress
Stress is also often accompanied by weight loss or increase. Increased stress levels affect various hormones: cortisol, DHEA and adrenaline. The hormone cortisol is often linked to weight fluctuations. Cortisol is necessary for the metabolism and it helps the body to deal with stress. It is therefore also called the stress hormone.
Cortisol affects blood sugar levels and thyroid function, and it can cause weight fluctuations and symptoms of poor metabolism, such as fatigue, depression, colds, reduced memory and poor concentration.
Relation cortisol and insulin
Cortisol and insulin are closely linked. If you experience a lot of stress, the cortisol levels increase considerably. If the cortisol level is too high, cells can develop resistance to insulin, resulting in increased blood sugar levels. This can cause weight gain and even Type 2 diabetes.
After cortisol has been raised for a longer period of time, it can collapse completely. If this happens, you feel completely disconnected. This is usually a sign of adrenal exhaustion. This can be caused by continuous and intense stress, consecutive periods of sleep deprivation and general lack of mental rest periods. Exhausted adrenal glands cause blood sugar levels to drop, resulting in hypoglycaemia, causing weight loss and low stress tolerance.
Cortisol and the thyroid gland
As mentioned before, cortisol also affects the thyroid gland. Cortisol levels facilitate the optimal hormone production of the thyroid gland with a healthy metabolism as a result. Too high or too low cortisol levels, however, cause a slow thyroid function with symptoms of poor metabolism and weight gain.
The cortisol abdominal fat cycle is a vicious circle and works as follows:
We feel stressed so our body releases cortisol that gives us energy
- our cells require more glucose and tell our brain to feed them
- we eat based on these triggers in our brains
- we become heavier and feel stressed about this weight gain.