This article has been Fact-Checked by Kendall Kennedy MS, RD, RYT
Losing weight by fasting has a lot of potential if you do it right. However there are a few things you have to keep in mind or fasting could have unhealthy consequences.
Fasting consists of not eating and in some cases even not drinking for a certain amount of time. It is something that has been done for at least 1000’s of years. Both for health and religious reasons.
The advantages of losing weight by fasting
There have been done a lot of studies on fasting both in humans and animals. It has been getting more and more attention due to the fact that the results of the studies have been very promising.
Fasting has a lot of benefits for weight control, health in general and it might even help you live longer.
Here are some of the main advantages of fasting:
- Weight Loss: Fasting has a lot of potential for helping you lose weight if you do it the right way.
- Insulin resistance: Fasting can help you reverse insulin resistance. This in itself is extremely important for a lot reasons, including a lower chance to get type 2 diabetes.
- Cancer: Animal studies show promising results of using fasting to battle cancer.
- Anti-aging: Fasting in rats made them live 36-83% longer.
Knowledge about fasting is still growing but at least some periods of fasting looks like a very good tool to improve your weight and health.
Is fasting to lose weight right for you?
Some habits are good for the majority of people but not for a small group. You should always consult with your doctor before making any radical changes in your lifestyle.
In the case of fasting this is extra important if you:
- Have diabetes
- Problems with your blood sugar
- Are a woman who is trying to conceive
- Are a woman with a history of amenorrhea
- Pregnant or breastfeeding
- Are underweight
- Take medications
- Have low blood pressure
Fasting for an extended period of time, or even a short period if you’re not used to it, can make you feel weaker and less alert. It might be good to avoid heavy tasks or things like driving on moments like these.
Things you need to do before you start
The first thing you need to decide is what kind of fasting you want to do. Weirdly enough there are a lot of ways you can do not-eating.
The next step is considering whether or not you will need to supplement with micronutrients. Your body can only store small amount of some vitamins and minerals. It might not be a bad idea to supplement electrolytes for example.
If you are planning on fasting 24 hours or less this normally isn’t a concern. But if you plan one any longer than that, you might need to consume some micronutrients during your fast.
There is another thing you can to reduce the possibility of a micronutrient deficiency during your fast. Make sure you eat a wide variety of whole foods before you start. This way your body will atleast have some micronutrients stored to use during the fast.
Finally, having something to do during your fast is extremely helpful. It often happens that your body will start craving for food. Preparing some activities can help you keep your mind off food.
The easy part
When you’ve completed all the previous steps it’s time for the main event.
Depending on what type of fasting you are doing, you can consume zero calorie drinks like coffee and tea. Fasting isn’t a ticket to drinking 20 cups of coffee a day, too much, about more than 5 cups, can still kick you out of your fast.
Remember, if you physically start feeling bad, it might be time to end the fast. It’s hard to give specific guidelines on this part since everyone will feel different. You need to listen to your body.
Careful when you start eating again
By the end of your fast one of two things will happen. Option one is that you want feel hungry at all. Option two is that you feel like you can eat an entire buffet.
In both cases you’ll have to ease back into eating. How cautious you have to be depends among other things on how long you’ve been fasting.
Normally, you won’t have any problems with eating again up to a 24 hour fast. Any longer than that and you’ll have to be a bit more careful.
Refeeding with nutritious whole foods is extremely important. By now your body probably has low amounts of certain micronutrients.
Start off with small portions of easy digestible foods
By fasting your body has removed bad tissue from your body. This is a good thing but now, after your fast, you want to be able to build good tissue to replace the bad tissue.
The best food groups for this are protein and carbohydrates. Even if you are on a low carb diet you might want to eat carbohydrates for once. Complex carbohydrates like for example oats are perfect.Try to stay away from processed foods high in sugar.
A few examples of foods you can consider are water-rich vegetables, avocados, oats, eggs, yogurt,..
Again it’s very important to not stuff yourself too much right from the start.
Eat a little bit. Wait 30 minutes. If your body reacts well to it you can eat some more. Wait again. And so on. There is no one right formula for this. Everyone reacts differently so you’ll have to listen to your body.
How often should you do fasting to lose weight?
If you get to this part you will know how great fasting can feel both physically and mentally. Before you go at it again you have to consider a few things.
Take a look back to how your fast went. Write down what didn’t go well, what things made your fast better and so on. If your fast lead to binge-sessions you have to change something. Fasting might not (yet) be for you.
Some people start using fasting as a “punishment” tool for when they overeat. Make sure this isn’t you and plan out your future fasts calmly.
Then before you do another fast you have to replenish your body’s vitamin and mineral stores. How long this will take depends on what you eat and how long you’ve fasted. You also need to give your body time to recover from the stress of fasting.
The message is rather safe than sorry.
Fasting is extremely good for weight loss when done right
Fasting is an extremely powerful tool in your weight loss toolbox and for your health in general.
You don’t have to do it for extended periods to see the benefits either. Even increasing the time you don’t eat for a few hours every day can benefit you.
As long as you do fasting right you should see and feel great results.