Physical Withdrawal from Nicotine
Studies have shown that nicotine affects blood chemistry in a couple of ways that influence appetite:
Nicotine and Adrenaline
When a person inhales cigarette smoke, the nicotine in the smoke is rapidly absorbed into the blood and starts affecting the brain within 7 seconds. The result is the release of the hormone adrenaline, the “fight or flight” hormone. Physically, adrenaline will increase a person’s heart rate, blood pressure and restrict flow to the heart muscle. The smoker will experience rapid, shallow breathing. Adrenaline also instructs the body to dump any excess glucose into the bloodstream.
Nicotine and Insulin
It is thought that nicotine also inhibits the release of the hormone insulin, which is responsible for removing excess sugar from a person’s blood. Between excess glucose from adrenaline and the inhibition of insulin, smokers are slightly hyperglycemic, meaning they have more sugar in their blood than usual. And because blood sugar acts as an appetite suppressant, smokers don’t usually feel hunger as often as non-smokers.
There are several reasons why ex-smokers turn to food when they quit smoking:
Emotional habit: Years of smoking taught us to react to literally everything by lighting a cigarette. When we were happy, we'd celebrate by lighting up. When we got angry, smoking would calm us down, or so we thought. Tired? Smoke a cigarette to stay awake. Hungry? Feed yourself a smoke. We always reached out for our cigarettes no matter what.
Meal skipping: Smokers tend to be meal-skippers, especially at breakfast. Coffee and cigarettes don’t make a good meal, and once we quit, eating regular meals again may add extra calories that weren't a part of the diet.
Food tastes better: Without the mask of cigarette smoke covering our taste buds, food is a lot more appealing!
Comfort: Nicotine withdrawal is uncomfortable, and food, for most people brings an almost immediate feeling of comfort and well-being.
Hand-to-mouth habit: How many times a day did you lift your hand to your mouth when you smoked? You'd be surprised how ingrained that action can be, and how fidgety you might feel when you’re no longer doing it. Putting food in the hand as it goes to your mouth is a common substitute!
Withdrawal from nicotine is uncomfortable
You need to expect that you’re going to want to replace the action of smoking with a substitute, and food is often the choice we make. The trick is not to let snacking get out of hand. Finding a balance is important because eating too much and gaining an excessive amount of weight could lead you right back to smoking.