What Experts Are Not Telling You About Overeating One Day

February 21st 2020

We’ve all done it; we overate on one day. Now, the question remains, should we fast the next day? 

Whether it be due to a holiday, a season of stress, a season of celebration or for no particular reason at all—we’ve all found ourselves at the end of a long day feeling overstuffed, bloated, and slightly guilty. 

Overeating isn’t a pleasant part of life, but it is something that humans do. What’s important to figure out is what we do about it.

Aside from putting together strategies to reduce the number of occasions we overeat, we should figure out what our next-day strategy to help metabolize all of those extra calories should be. 

What should our activities on that next day entail? 

Should we fast? 

Should we work out extra hard? 

Should we do nothing at all? 

In this article, we’ll look at some of the science behind overeating, gaining weight, fasting, and what we should do to make all of that work in our favor. 

What constitutes overeating? 

The experts at the Universtiy of Pittsburgh Medical Center Bariatric Center state that overeating is simply “eating more calories than your body uses for energy.” 

They go on to note that there are many reasons that people typically overeat, which can extend all the way from extreme stress to mere boredom.

As their definition indicates, what may be overeating for one person won’t be overeating for another, as it’s based on your specific body as well as your unique activity levels. 

As a general rule of thumb, if you’re extremely active, or if you know that you have a high metabolism, you should eat more. 

However, if you have a slower metabolism or tend to be less active during the day (for example, if you have a sedentary job), then you won’t need to eat as much.

However, that’s an extremely general definition. 

How can you tell how many calories your body uses for energy, and how can you tell if you’re eating more than that magic number? 

The Utah Department of Health has released a handy tool to help you figure out the answer to this all-important question. 

According to their system, you start by estimating your Basal Metabolic Rate, which can be found by the following equation: 66+(6.3 times your bodyweight in pounds) + (12.9 times your height in inches) - (6.8 times your age in years). 

Simply plug in your weight, height, and age and the number you get will be your relatively accurate basal metabolic rate.

Then, take your basal metabolic rate and multiply by the following activity factors: 


  • If you’re relatively sedentary, multiply your basal metabolic rate by 1.2.
  • If you do light activity during the day, multiply your basal metabolic rate by 1.375. 
  • If you consider yourself moderately active, multiply your basal metabolic rate by 1.55.
  • If you are a very active person, multiply your basal metabolic rate by 1.725. 
  • And, if you’re an athlete or have a very physical job, multiply your basal metabolic rate by 1.9. 

That will give you your caloric needs for maintaining your current weight. 

If you hope to gain or cut, you’ll have to tweak that number up or down, as appropriate. 

Now, we have an answer to the question above!

If you regularly eat more than the number you computed (as deemed by calorie counters of your normal eating habits), then, yes, you are overeating. 

What happens in your body when you overeat? 

The folks at the University of Texas MD Anderson Cancer Center say that overeating “causes the stomach to expand beyond its normal size to adjust to the large amount of food”, along with forcing all of your organs to overwork themselves to metabolize the unusual load, making your stomach potentially overproduce the acid it makes to break down your food, making your stomach potentially produce more gas, and your metabolism going into overdrive (which can make you feel flushed and dizzy). 

In short, it’s an unpleasant experience! 

However, if you only overeat for one day, your body does have mechanisms in place to help compensate—which is a good thing. 

The problem comes when you overeat for a long period of time and your body interprets that as the new normal. 

Avoid that at all costs. 

If I overeat one day, should I fast the next? 

The short answer is—no. Because, as we covered above, your body knows what to do in the event that you have eaten more than you should, if you simply go back to making good choices after the overeating event, your body should be fine. 

A good example of this is the holidays: 

While you should try to make healthy choices where you can, if you overeat by a little bit in December but go back to your usual eating habits in January, you should be fine.

However, if you have specific goals about losing weight, you may feel inclined to fast in order to undo the damage you may think you have done. 

As covered above, this is probably unnecessary; however, if you’re trying to lose weight, some premeditated fasts likely wouldn’t hurt, as long as you’re doing them sensibly. Harvard's School of Public Health touts the benefits of intermittent fasting as a weight loss tool—but it isn’t something that you should take on as a punishment for overeating for one day. 


Will I gain weight if I overeat one day? 

Initially, yes, you will gain weight due to consumption of a surplus of calories for one day. However, it’s likely not a big deal—over time, especially if you return to your good habits, that weight will balance out and you’ll start to see a return to the weight you were before you overate. 

Fasting for one day won’t necessarily cancel it out! 

Should I eat more if I am lifting weights? 

The short answer is—yes.

Even if you are trying to meet some pretty stringent weight loss goals, if you’re going to be starting any kind of intense weightlifting regime, you need to make sure that your body has enough energy to be picking up those loads. 

You might notice that you get even hungrier when you are strength training.

This is a very common reaction when your body is exerting itself more.

Also keep this in mind as well:

If you’re lifting weights, you shouldn’t be starving yourself. 

It might seem like a good strategy for weight loss, but in reality you’d be burning both ends of the candle. 

If you want to be building muscle, you need protein in your diet—which, of course, means that you need a normal, healthy diet to begin with! 

As you continue along in your health journey, whether that means losing weight or bulking up or simply moving your body and picking up your weights every day, make sure that you’re listening to your body and making the choices that are right for you.

 Know that you’re human and you’ll make mistakes—and that’s okay! However, having the self-control and initiative to acknowledge that you messed up one day and are still worth investing in the next is the magic ingredient that will make all of your fitness goals come true. 


If you overate, do not stress about it.

Unless it becomes a habit, your body will return back to normal after a few days.

On the scale, it may seem as though you are gaining weight.

But if you keep everything constant, you will find that your appetite for the next few days slightly decreased.

As a result, in a week’s worth of time, you have eaten the same amount of calories as before. Or similar at least.

Your body is a very efficient machine and it does not want to store excess energy for no reason.

Especially if you are lifting weights, eating healthy regularly, one or two splurges to enjoy yourself will not drastically disrupt your progress.

Tags Lifestyle

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