Can Smoking Make You Fat?

Smoking and consuming nicotine can affect your blood sugar and impact your appetite.
Smoking can impact how your body functions in general. It increases carbon monoxide in
your body, which decreases oxygen levels. Carbon monoxide (CO) is an odorless,
colorless gas formed by the incomplete combustion of fuels.
When people are exposed to CO gas, the CO molecules will displace the oxygen in
their bodies and lead to poisoning. Smoking can speed up and put pressure on
your heart and it also slows down circulation due to your blood becoming

Nicotine, the highly addictive substance in tobacco and some vaping products, is a psychoactive substance.This means it affects how the brain works, as well as how your body works. Nicotine releases stress hormones in the body and triggers your ‘fight or
flight’ response. This affects your appetite in many different ways, which in
turn can affect your body weight.

How smoking affects your body weight:
Smoking is linked with both weight loss and weight gain. Studies show that long term
and heavy smokers are more likely to be overweight or obese than those who
don’t smoke.
1. Appetite
Nicotine causes your body to release cortisol, the main stress hormone. Cortisol is used
in your ‘fight or flight’ response to what is seen as danger. Cortisol shuts
down systems in your body such as your digestive system and immune system. It
does this to preserve energy for either facing or running away from a threat.
If there is no threat, people might experience the following symptoms:

  • Anxious feelings 
  • Restlessness 
  • An inability to focus. 
  • Temporary loss of appetite

2. Blood sugar levels
The body releases cortisol when you smoke. Cortisol stimulates gluconeogenesis,
meaning it makes your body form glucose. Glucose is sugar and your body breaks
food down into glucose for energy. When you experience a spike in cortisol you
will also experience a spike in your blood sugar level.

Your body responds to a spike in blood sugar by increasing insulin to break down the
sugar. This can leave you with low blood sugar levels. People often crave
sugary foods and drinks when they experience low blood sugar levels. Sugary
foods will cause blood sugar to spike again and start the process again. Eating
sugary processed foods can have a negative impact on your health and sometimes
leads to weight gain.

3. Weight gain after you quit smoking
Sometimes people find that they gain weight when they quit smoking. This can be for
several reasons. Smoking triggers your ‘fight or flight’ response, and this can
suppress your appetite. When you quit smoking, you might crave the high that
nicotine gives you. You might try to get it from other substances like sugar or

People who stop smoking also recover a sense of smell and taste and so they may find
that they enjoy the taste and smell of food more than before. Smoking is also a
habit which involves hand to mouth action and when people stop smoking, they
may find that they replace smoking with eating things like sweets and
crispy/crunchy foods.

Here are a few things you can do to avoid or lessen weight gain after giving up the
habit of smoking:

  • Try to drink lots of water to help your body flush out leftover toxins. 
  • Eat something every three to four hours to regulate blood sugar. 
  • Make sure to have protein, healthy fats, high fiber foods, fruit or vegetables in each meal or snack. 
  • Try to keep a regular sleep pattern.

If you are craving sugar, try to have a piece of fruit instead. Have it with
protein and a healthy fat, such as peanut butter.