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.
Overweight and obesity develop over time when you take in more calories than you use, or when energy IN is more than your energy OUT. This type of energy imbalance causes your body to store fat. Your body uses certain nutrients such as carbohydrates or sugars, proteins, and fats from the foods you eat to: