Study Review: Short-Term Overeating Does Not Increase Fat Percentage

Study Review: Short-Term Overeating Does Not Increase Fat Percentage

The year is ending soon. And that means everyone is planning their year-end holiday trips right now.

One thing I hear a lot is that people often think that going on holiday means “getting fat” because of all the eating they’ll be doing.

The question is, what are the effects of overeating in a short period of time, and does the weight really stay on?

Interestingly enough, there is a study done on this in 2014.

The Method

Ten healthy Japanese men consumed a surplus of 1,500 calories over their regular consumption for 3 days.

To put it into perspective,1,500 calories is 3 Big Macs worth of food on top of their regular meals.

The study did not specify what foods they ate exactly as their diet was self-selected to fit with their lifestyle.

The schedule of their diet is detailed in the figure below:

On top of that, subjects measured their own body weight twice daily, 6 days before the overfeeding period and also 2 weeks after the overfeeding period.

The Results

As expected, total body weight did increase during the period of overfeeding.

Calories in, calories out. If you eat a surplus, your body will definitely gain more weight.

But are all causes of weight game the same? To most people, the answer is yes.

The moment they see numbers on the weighing scale increase, they freak out.

Truth is, some forms of weight gain are easier to lose than others. As I’ve written here before, a more accurate indicator of health and aesthetics is to reduce fat percentage or fat mass, not just weight.

And the results of the study shows that overfeeding for 3 days out of the 4-week period did increase total body weight, but not fat mass or fat percentage.

What actually caused weight gain was mainly total body water (or water weight) and fat-free dry solids.


Many people don’t take into account water weight’s role in weight loss. They assume that as long as they weigh less than they want to be, that’s a good thing.

However, water weight fluctuates wildly depending on the time of the day you measure your weight.

What is a true indicator of health and fitness (especially if you want to look good), is always fat mass and fat percentage.

If you want to get abs and look toned and tight, fat mass is what you should focus on reducing.

And this article will show you how.


All in all, if you’re planning a short holiday trip this year-end, don’t worry about gaining weight.

Of course, that doesn’t mean you should go nuts. Spread out your caloric intake. But it’s fine if you eat a little more.

Long-term consistency is what truly matters. Obesity doesn’t just happen overnight.

It happens through long, sustained unhealthy habits over years.

And the same goes for fitness. You don’t just become fit because you diet for a short while.

Everything is the cause of long-term habits. And even if you eat less, you might lose weight, but that doesn’t make you fit.

Some skinny people do have high fat percentages too (i.e., skinny fat).

If you found this article useful and you want to start your fitness journey, let us give you all the tools you need to get started.

Come down and meet our fitness experts for a free power hour session where you will get a workout and nutrition roadmap, take your body measurements, and also a mobility assessment.

Go here to book your session now.

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