6 Side Effects Of Fasting Or Skipping Meals On Your Body

Meal skipping or fasting can help give your body a reboot. There are lots of reasons for you to try this once in a while, but it’s important to also be aware of the flip side of fasting. On the one hand, you could benefit by lowering inflammation in the body or burning more fat during a workout. But on the other, if you are at risk of developing insulin resistance or diabetes, or are looking to lose belly fat, skipping meals is the last thing you should do.

So here’s a look at why you should try it and when you shouldn’t!


1. It Can Treat Your Asthma

Adults with mild forms of asthma who are also overweight could get some respite from symptoms when they skip a few meals. One study followed a meal skipping plan that required overweight adults who had mild asthma to give up the equivalent of one meal a day or around 400–500 calories on one day, with a regular meal plan the next. Besides improvements in asthma-related symptoms like breathing, the participants also saw reductions in oxidative stress levels and an overall reduction across inflammation markers.1

2. It Could Cut Inflammation Down

Fasting, a tradition followed in many cultures and religions, may have benefits for brain function, inflammation, and your metabolic system too. According to researchers from the Salk Institute, when you fast, even if just for one meal, it could help with problems linked to inflammation, including arthritis, inflammatory bowel disease, and even cancer. While further study is warranted, early results are promising.2


3. Fast And Exercise: Yes And No!

When it comes to fasting and exercise, things could swing either way. On the one hand, if you exercise on an empty stomach, you may see higher calorie burn. One study noted a 20 percent higher fat burn during a workout done on an empty stomach. This theory, however, may apply well to those who work out in the morning and have had a healthy, balanced dinner the previous night.3

The other side to this story is that you may run out of steam by the time it’s workout time! If you tend to work out later in the day and have skipped some meals before that, energy levels may dip. It may even be hard to find the motivation to get moving.


4. It Can Increase Cortisol Levels

There’s a reason dieters aren’t the happiest bunch. You might think the low sugar levels are to blame, but the answer to that infamous feeling of being “hangry” or angry from hunger lies in your stress hormone balance. When you skip meals, your body’s levels of stress hormone cortisol spike. And while cortisol at normal levels is needed to help you respond to stress better, too much of it can weaken your immune system, mess with your endocrine system, and even slow down healing.4

5. It Can Help You Lose Weight But Gain Belly Fat

If weight loss is your primary goal, meal skipping may not be a long-term solution. While it can help you knock off some pounds in the short run, you are likely to gain them back once you return to your regular diet. Worryingly, according to research, you may even end up with belly fat where there once was none. That’s because your weight loss could be a result of muscle loss. This in turn could hurt your metabolism and cause more fat accumulation. And that’s why, ironically, a weight-loss solution is the one thing that meal skipping is not.


One study on animal test subjects found that when they skipped meals in the early days of the study and were later given all meals, they developed a tendency to binge eat or gorge. They ended up consuming all of their fixed quota of food in 4 hours and, as a result, fasted for the next 20 till their next day’s food supply was restored. It also caused these animals’ body inflammation to increase. Genes that cause fat storage, especially in the abdominal region, were activated more.

Nibbling through the day and not skipping meals may, therefore, be a better alternative if weight loss is your aim.5


6. Do Watch Out For Insulin Resistance Or Lower Glucose Tolerance

When you miss meals regularly, you develop unwanted abdominal fat which researchers have linked to cardiac disease as well as type-2 diabetes. Fasting causes insulin to drop. Without insulin to stimulate the liver and work as a signal, the body won’t know when to stop glucose production, resulting in major ups and downs in blood sugar levels in your body. In one study of middle-aged men and women, subjects used meal skipping and consumed just one large meal a day. Over the 2-month window, their morning glucose tolerance was impaired, insulin response was delayed, and fasting glucose levels were elevated. However, this impairment was reversible. In other words, if you go back to a normal diet with regular mealtimes and no fasting, you should see your morning glucose tolerance, insulin response, and fasting glucose levels return to normal.6