Final answer:
Smoking is hard to quit due to the addictive nature of nicotine. Nicotine suppresses appetite, making people less hungry.
Step-by-step explanation:
Smoking is hard to quit because nicotine, the addictive substance in cigarettes, affects the brain and causes a strong physical and psychological dependence. When a person smokes, nicotine binds to certain receptors in the brain, releasing dopamine and creating a pleasurable sensation. Over time, the brain becomes accustomed to the presence of nicotine and craves it, leading to addiction.
As for the effect of smoking on hunger, nicotine is known to suppress appetite. It stimulates certain areas of the brain, such as the hypothalamus, which regulates hunger and satiety. Nicotine can reduce food cravings and make people feel less hungry, leading to weight loss.