The question raised here may sound or look absurd to the untrained eye/mind - why would anyone consider a 2-days weight loss plan in the first instance? But inquiries such as these are not strange to an experienced or practicing fitness doctor. And, the truth is that s/he must find a way of addressing the client's concern - albeit professionally.
It is from this standpoint that I shall be exploring the possibility of shedding some pounds in 2 days. As you might have experienced in life; humans can achieve whatever they determine to do. Looking at this within the context of weight loss; one can lose as much weight as the body might allow. However, consistently subjecting the body to extreme and/or rapid weight loss may come at a huge cost - a detrimental effect on one's overall health. In light of this, I shall be considering the probable number of pounds that can be lost by following a slow or rapid weight loss regimen.
Slow 2-days weight loss regimen
By slow or gradual weight loss regimen, I ascribe to the 1 - 2 pounds per week recommendation proposed by the Centers for Disease Control and Prevention (CDC). An individual who sticks to this routine would only be able to shed off a meager 0.28 - 0.56 pounds of weight after 2 days - how inconsequential you may say. And, the truth is that no serious or meaningful weight loss outcome can be attained from this sort of short-spanned routine.
Rapid 2-days weight loss routine
Now, this is the focal point of this discourse. Pardon me for taking that detour - the enlightenment was worth it, nonetheless. Whenever folks get to ask about the weight they can lose in a short span, the intention is, more often than not, to go on a rapid weight loss routine.
In this case, an individual may aim to lose 2, 4 - or maybe more - pounds in 2 days. This can be actualized through embarking on different forms of fasting or extreme dietary restrictions.
Dry fast
Dry fasting means not eating or drinking water for a specific number of hours or days. But going without water for 3 or more days is not advisable – the body should not be allowed to be dehydrated for that long. Moreover, as the body is deprived of water, the cells will begin to shrink, and this could have grievous consequences on the kidney. Brain swelling and seizures are other problems that may arise with extreme or continued dehydration.
So, bearing in mind that we can consume about 2,000 – 2,500 calories daily on average; an individual who chooses to go on a dry fast for two days could give up 4,000 – 5,000 calories. This would mean losing 1.14 – 1.43 pounds of weight. It can, however, be more if the person chooses to also add some exercises, but this will be very risky. Fasting and (excessively) exercising can cause significant metabolic dysfunction. One can even suffer various heat-related problems by doing so.
Water fast
A person may yet choose to abstain from eating but drink water during the period of the fasting that may last for some hours or days. It is reported that water is valuable in weight loss, especially for people that may be on a very low-calorie diet. The number of calories that anyone embarking on a 2-day weight loss routine this way will be similar to that of a person doing dry fasting although the probability of getting dehydrated is eliminated.
Alternate day fast
In this respect, an individual chooses to go 24 hours without food and eat the next day – but the calories that would be so consumed must not be more than 500. This is yet another means of extreme calorie restriction that can see one losing up to 1 pound in 2 days.
Other forms of intermittent fast
It is yet possible for an individual to abstain for a specific number of hours in a day and then set the remaining hours aside for food consumption. For example; the 16:8 hour fast will have one fasting for 16 hours and then eating within the remaining 8 hours of the day. The calorie deficit created this way will be quite considerable, and it may be possible to lose 1 or more pound(s) of body weight by adopting this method of fasting. Apart from the example cited above, this form of fasting can be defined in other ways: 12:12 hour fast, 17:7 hour fast, 15:9 hour fast, and so on.
What happens during fasting?
In the first 12 hours of observing a fast, glycogen stores normally undergo depletion to release glucose that fuels metabolic functions. Glycogen, by the way, refers to glucose mass in its stored form. It should not go without saying that as the glycogen store is depleted, the body experiences significant loss of (body) fluids. That said, if you decide to continue fasting after the 12 hours, the body will have no choice but to resort to the stored fat which is ultimately released as energy to continually power the metabolic activities. It is as this accumulated fat – which is responsible for weight gain in the first instance – is burned that a person’s body weight drops.
Final words
Weight loss is supposed to be done purposefully to sustain the outcome and achieve a healthy weight – with the BMI being within the normal range. So, as you decide to go with a 2-days weight loss routine, you should have clarity about what you are aiming to achieve. Is it about just trying something new – maybe to see how your body will react? Or are you looking to do it intermittently? None of these will ensure long-term success. Moreover, you should never forget that engaging in rapid weight loss programs – especially with fasting involved – is never without specific health consequences. Plus, you might just end up overstressing your body in the process.
References
Catenacci VA, et al. (2017). A randomized pilot study comparing zero-calorie alternate-day fasting to daily, caloric restriction in adults with obesity. Obesity (Silver Spring) 24(9): 1874 – 1883.
Lowe DA, et al. (2020). Effects of time-restricted eating on weight loss and other metabolic parameters in women and men with overweight and obesity: The TREAT Randomized Clinical Trial. JAMA Internal Medicine 180(11): 1491 – 1499.
Stockman MC, Thomas D, Burke J, and Apovian CM. (2018). Intermittent fasting: Is the wait worth the weight? Current Obesity Reports 7(2): 172 – 185.