N2 nicotinic receptors are found in the brain, plus the autonomic and parasympathetic nervous systems [1]. Different subunits make up these two types of nicotinic receptor, which is why we consider them separately. Muscarinic receptors have a different mechanism of action.
Your body weight can regularly fluctuate, but the persistent, unintentional loss of more than 5% of your weight over 6 to 12 months is usually a cause for concern. You should pay particular attention if you experience other symptoms, such as tiredness, loss of appetite and a change in your toilet habits.
If those calories are not used, the body stores them as fat. Your body will build up fat stores if you continue to eat more calories than your body can use during daily activities and exercise. Obesity and morbid obesity are the result of too much fat being stored in your body. Certain medications, such as antidepressants, can cause weight gain. Medical conditions such as hypothyroidism can also lead to weight gain, but can usually be managed so that they do not lead to obesity.