You can be eating healthily and exercising regularly but still have problems maintaining a healthy weight. If this sounds like you, you might need to look a little deeper to determine whether your hormones are making you hungry.
Factors that influence hunger and appetite
Several factors can affect the way you consume food e.g. your existing eating habits, external cues and emotions - these are co-ordinated via the interaction of complex body systems involving the gut, brain and hormones. Genetics, the environment, lack of sleep, chronic stress, crash dieting or fasting, hormonal imbalances and your level of physical activity can also influence your hunger and appetite.
Difference between hunger and appetite
- Hunger is the physical need to eat, caused by chemical changes in your body i.e. hormones, neurotransmitters and neuropeptides. Hunger enables you to eat just enough to meet your body's nutritional requirements.
- Appetite is the desire to eat, caused by sensory or psychological reactions that stimulate an involuntary response allowing you to override feelings of hunger and overeat.
- Grehlin tells you that you're hungry. Chronically elevated levels of grehlin drive increased appetite, sugar cravings, overeating and increased risk of storing calories as fat.
- Neuropeptide Y (NPY), in conjunction with grehlin, really drives up appetite. NPY dictates where and how extra calories will be stored in your body and delays that feeling of fullness after eating, allowing you to eat more. Stress stimulates the release of NPY, further increasing the storage of fat.
- Leptin is produced by fat cells in your body and when levels are high, you feel full and satisfied after eating. In other words, it puts the 'brakes' on your appetite. Long term obesity and stress disrupt leptin activity. When cells don't react to leptin signalling, there is leptin resistance, where the body is unable to detect signals of fullness, leaving you feeling hungrier, more often.
- Cholecystokinin (CCK) is released as food enters the stomach, helping to slow down the movement of food and delaying gastric emptying so you feel fuller for longer. It takes more than 10 minutes for food to stimulate the release of CCK. Eating processed foods which are typically 'calorie rich' and can be consumed very quickly, makes it easy to overeat before the effects of CCK are felt.
- Serotonin is often thought of as a brain chemical to regulate mood. However, serotonin is also involved in the regulation of eating behaviour and appetite control, and decreased serotonin levels increase your appetite for carbohydrates. Dysfunction in the 'gut-brain' axis can impact the production of serotonin.
- Garcinia cambogia is widely used to make meals more filling and as a food preservative and flavouring agent. The fruit rind is rich in hydroxycitric acid (HCA) and most good Garcinia supplements will have HCA standardised to 60%. HCA is responsible for the herbs activity in helping to maintain a feeling of fullness and satiety. HCA also supports fat metabolism and assists abdominal fat loss.
- Caralluma is an edible cactus with a long history of use as a natural appetite suppressant. In fact, it is considered a famine food, eaten by traditional hunter-gatherers to suppress hunger and thirst on extended hunting trips. Caralluma is traditionally used in India to reduce hunger and suppress appetite.