Why is fasting is popular for weight loss?
So flash back to my college days. Here I was, awkward in my body, feeling anything but sexy and thinking that all of my problems could disappear easy peasy if I could snap my fingers and become a skinny girl. I just needed to figure out how to lose weight for long enough and in a consistent enough way to reach my goals. I was stuck in this body that I didn’t feel should be mine. And fasting seemed like the perfect answer.
I’ve tried a couple of approaches to fasting. In the first version, I would go a few days without eating anything. Sure, I would feel weak and light-headed and miserable. But if I could just shed a few pounds quickly, then I could lose the rest with responsible dieting. And fasting would be a great jump start to help get me on my way.
The second approach was daytime fasting. I wouldn’t eat at all during the day to save my calories for dinner. And yes, I would have a somewhat larger dinner. But eating one large meal would still mean consuming fewer calories over the course of the day than eating 3, more reasonably sized meals.
I would lose weight. Fasting just never helped the weight to stay off.
Science and Fasting
The month-long celebration of Ramadan has provided researchers with very helpful information about the act of fasting and its impact on weight. During the month, observers abstain from eating and drinking until sunset on a daily basis. Fasting is then followed by compensatory overeating to regain energy stores. This is often marked by weight gain and high levels of plasma lipids without an increase in total calories. 
So what is going on here? Why does fasting lead to weight gain when overall food intake is decreased?
It really comes down to something as simple as hormonal interaction. You have hormones in your body that tell you when you’re hungry when you’re full, and how much fat your body should store. Much of your extra weight is the fault of a malfunction in this hormonal system. All these hormones work together, and if one of them isn’t working correctly, none of them will.
As you might imagine, not eating all day increases the hunger hormone to very high levels. This puts your body into starvation mode. And when your body is starving, it wants to conserve energy. Resuming eating will signal your hormone to go into fat storing mode. And this makes it possible for everything you eat to be turned directly into fat. Ever have a friend who complains that she don’t eat anything but is gaining weight? Now maybe you’ll believe her.
The bottom line about fasting for weight loss
If you have an event in a few days and your dress feels a little tight, fasting may help it fit perfectly by the day of the event. Just plan to gain all the weight back, with possibly a little extra by the time you go back to normal eating. I personally wouldn’t recommend this approach. But if your goal is to lose quick, temporary weight, fasting could be effective. But if you are looking at fasting because you want to feel confident, sexy and healthy on a daily basis, fasting, in my opinion, isn’t the way to go.
I know that you might be nervous to consume calories earlier in the day for fear that you’ll overeat in the evening. Evening tends to be a time when diets can unravel and a day of discipline can evolve into a nighttime binge. And last week I talked about preparing for such obstacles in your weight loss plan. But what I say next may shock you.
Even if you take in extra food through a nighttime binge, it is better for your waistline to eat consistently throughout the day than to daytime fast. Your overall caloric intake may be higher than if you didn’t eat in the morning. But you probably won’t store quite as much fat. And since your hunger hormones will be more in balance, you might not binge to such an extreme.
Fasting is tempting as a quick fix for extra pounds. I get it and I’ve totally been there. It is also an unavoidable part of many religious rituals and I’m certainly not recommending deserting your religion But I hope you now see that fasting probably won’t lead you to the results you’re really looking for weight loss. Eating early in the day (preferably within a half hour of waking) is a wonderful way to establish proper hunger and fat storing signals for the day. And a more moderate diet, filled with good quality protein, fats, and carbohydrates will be a more effective weight loss journey for the long term.
- Han, JM, Kim, HG, Lee, JS, Choi, MK, Kim, YA & Son, CG. (2014). Repeated sense of hunger leads to the development of visceral obesity and metabolic syndrome in a mouse model. PLoS one. Vol 9(5). 0098276.
Sabrina Quairoli says
Thanks for sharing this post. I can only fast if I have eatten a lot the day before. My blood sugar goes to low and I can’t concentrate at all. It’s horrible.
Sabrina, it is so true that if you have imbalanced blood sugar, you will feel horrible the second you take too long of a break from eating. And if you have very imbalanced blood sugar, like with a diabetic, it can be life threatening.
I do not feel fasting should be used as a dieting method. I have read many female celebrities take to all sorts of fasting before attending red carpet events.
I fast every three months for religious purposes (I am a Christian). I break my fast at 6pm in the evening. It can mess up your eating patterns as your body is being “starved”. Our reasons for fasting is to
Withhold from the body, what it is used to, thus making us more sensitive to the things of God.
Celebrities do a lot of juice fasts. They are getting paid to look like a hanger. I live in Los Angeles so I see the pressure that people in the entertainment industry are under. Having said that, what celebrities do falls into the category of effective short term, but not good for the body and impossible to keep up long-term. Many celebrities also end up with eating disorders.
Not to long ago I had to go for a medical procedure that required no food for the previous 24 hours. The morning of the procedure I passed out while sitting in the waiting room. So fasting is definitely not something I recommend. Even though it was involuntary, it sure didn’t work for me.
Lenie, that is a long time to go without food. I hope you don’t have to do that test again.
Fasting is not in my cards. Anything you do in excess of which fasting is, one has to realize that there are down sides. Want to lose weight drink alot of green tea as it is a diuretic and doesn’t cause weight gain.
Green tea has lots of healthy antioxidants and is one of the better choices if you choose to drink caffeine. I would be hesitant to recommend drinking more than a couple of cups a day. A couple of cups a day can be healthy. People often drink green tea for weight loss in concentrated forms for the caffeine. And while high levels of caffeine can speed-up the metabolism short-term, it can be damaging to the adrenals long-term. And when you’re adrenals are shot. you’ll have weight gain and a whole bunch of even worse problems.
Erica- I really do not drink green tea for weight loss but more for the healthy antioxidants. Good to know about the adrenals. Thank you
Ken Dowell says
Interesting post Erica. For about the first 40 years of my life I was skinny and no amount of excessive or unhealty eating seemed to change that. Combine that with the fact that I’m not religious and the result is that I never considered fasting. As I got older I gained weight but not enough to take what I would consider an extreme measure like fasting.
Ken, I think the most common kind of fasting for weight loss is not eating in the early hours to save calories for later in the day. Most people probably don’t even consider themselves to be fasting. They just think they are “saving their calories”, but unfortunately weight loss doesn’t work that way.
Marquita Herald says
I was a real chubby girl when I graduated from high school so I tried many diets and I do recall giving fasting a try but only once and I’ve never considered it again, or dieting for that matter. But it is interesting to learn more about it. In fact now that I think about it I’m going to forward this to my niece who swears by fasting. Thanks!
Marquita, I hope this is helpful to your niece. I think we definitely do things like this a lot more when we’re younger. But it is sad that so many young people hurt their bodies in this way.
Though I have never fasted in my whole life, but I am well aware about the scientific benefits of fasting once in a while.
Fasting is regarded sacred in our religion (Hinduism) where people, mostly women fast before performing an auspiscious function.
Thanks for this informative post
Yes, I’m definitely not telling people to stop fasting for religious purposes. That is different because the goal is different and because there is a spiritual element that is meaningful to the individual. Fasting is difficult when being done strictly for weight loss because it usually doesn’t work.
William Rusho says
I am now on a strict diet.
I also will admit fasting, but this is different than what most people think of it. I went on a solid food fasting, this was decades ago, when I was a completive bodybuilder. Drinking only fluids for couple days, today they might call it a juice diet.
I also would only do this for a day or two, but it did help reduce bloating.
thank you for sharing this with us, and I hope people realize the dangers of full out fasting.
William, I thought of you when I wrote this article. I know a lot of wrestlers and bodybuilders incorporate fasting to achieve their goals. And while it isn’t healthy, at least the goals are short term (meaning that they only expect to lose temporary weight). So they aren’t being deceived into thinking they will get long term results. But you are right that it is very important for people to understand the dangers.
Jason Butler says
I have never thought about fasting. I’m naturally a skinny dude. I don’t need to lose any pounds.
Phew! great tip on fasting. I tend to try and fast to loose weight but now I know why I end up feeling bloated and even gain more weight. Thanks 🙂 great tips as always.