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Sunday Article 11: A Crash Diet: Good or Bad?


Diet culture is far from being a modern craze and in fact, this has been a historical obsession. The actual critical point of dieting came hand-in-hand with the arrival of newspapers and magazines back then. For decades, the mass media has been the one responsible for the surge of fad diets. There are countless triggers of dieting but one of them is definitely the images of super-slim figures circulating on the mass media platforms – imprinting the “ideal body” in the consumers’ minds (Fletcher, 2017). However, do you know that this trendy slim-down routine like a crash diet can terrifyingly backfire on our initial plan of losing weight?

Figure 2. Fruit juices. (Source: Pinterest.)

What is a crash diet?

A crash diet is generally a nutritionally unbalanced diet by excluding some (or all) crucial food groups to accomplish prompt weight loss results. There is a multitude of popular crash diets with a variety of names that could be found on the internet. 7-day detox diet, juice diet, and the keto diet, all of which consist of a very low-calorie diet (Bonet, 2020).

Why do people even crash diets?

While losing weight can usually be challenging and time-consuming, crash diets on the other hand often can offer a quick-fix solution to these troubles by “effectively” losing weight in just a few days with little effort. However, this very low-calorie diet is impossibly sustainable in the long run, so it is very much likely for people to revert to their old eating behavior (Bonet, 2020).

The backfire

Most individuals who undergo weight loss from calorie-restricted diets will likely regain (Anderson, Konz, Frederich, & Wood, 2001) or even worse, overshoot their initial body weight (Dulloo, Jacquet, & Giradier, 1997). As a matter of fact, approximately only 20% of individuals (who actually routinely practiced high levels of physical activity and restrictive diet) are successful at losing initial weight by at least 10% and at maintaining the loss for at least a year (Wing & Phelan, 2005). These frustrating observations are seemingly to persist after a huge weight loss and are often closely associated with compensatory mechanisms.

As mentioned before, dieting involves low-calorie intakes with the aim of rapid weight loss. However, massive weight loss in a short period of time complicates the maintenance of energy (calorie) balance; by decreasing energy expenditure and increasing appetite. These are the adaptations carried out by the body that exhibit compensatory behaviors. Collectively, these adaptations most likely lead to less than expected weight loss or (worse) weight relapse altogether (Doucet, Mclnis, & Mahmoodianfard, 2018).

Rapid weight loss appears to be closely associated with a permanent decrease in resting energy expenditure which can severely heighten the challenge to maintain the lowered body weight. In fact, based on a compilation of systemic reviews, it is reported that resting energy expenditure was reduced by ~15000 calories per 1kg lost (Schwartz & Doucet, 2010) after considering all types of interventions (e.g., dieting). Not only that, but upregulation in appetite seems to also persist for up to one whole year after the short-term intervention. Leptin could potentially be one of the modulators responsible for changes in appetite since it decreases with fat loss (Doucet, Mclnis, & Mahmoodianfard, 2018). Clearly, these adaptations – heightened drive to eat and reductions in energy expenditure – mark a further challenge to maintain weight loss after crash dieting.

So, which “healthy” diet actually works?

Weight is gained when the amount of calories intake is more than the number of calories burnt throughout the normal day-to-day activities.

An average man requires about 2500 calories a day while an average woman needs about 2000 calories to maintain the same weight.

(How to diet?, 2018).

With today’s advanced technology, daily calories can also be easily tracked with Total Daily Energy Expenditure Calculator by Fitness Volt.

Next, one of the means to lose weight healthily and maintain the loss is to make a permanent sustainable alteration to our diet e.g., choosing drinks that are lower in sugar and alcohol. Both sugar and alcohol are damagingly high in calories so cutting down the consumption can definitely help to control body weight(How to diet? 2018). Also, note that drastically discontinuing a certain consumption is also not an option as the taste buds are used to the previous eating habits. It takes time to make effective changes to diet routine so be patient (Fletcher, 2017). Thus, the key to a fruitful healthy diet is as simple as practicality and sustainability.

Great outcomes take time so do not give up and trust the process.


Anderson, J., Konz, E., Frederich, R., & Wood, C. (2001, November). Long-term weight-loss maintenance: a meta-analysis of US studies. The American Journal of Clinical Nutrition, 74(5), 579-584. Retrieved March 2, 2021, from

Bonet, A. (2020). Are crash diets ever a good idea for weight loss? Retrieved March 1, 2021, from NetDoctor:

Doucet, E., Mclnis, K., & Mahmoodianfard, S. (2018). Compensation in response to energy deficits induced by exercise or diet. Obesity Reviews, 19(S1), 36-46. Retrieved March 3, 2021, from

Dulloo, A., Jacquet, J., & Giradier, L. (1997, March). Poststarvation hyperphagia and body fat overshooting in humans: a role for feedback signals from lean and fat tissues. The American Journal of Clinical Nutrition, 65(3), 717-23. Retrieved March 2, 2021, from

Fletcher, V. (2017). The evolution of: dieting. Retrieved March 1, 2021, from Reader's Digest:

How to diet? (2018, October). Retrieved March 3, 2021, from NHS:

Schwartz, A., & Doucet, E. (2010, July). Relative changes in resting energy expenditure during weight loss: a systematic review. Obesity Review, 11(7), 531-47. doi:10.1111/j.1467-789X.2009.00654.x

Wing, R. R., & Phelan, S. (2005). Long-term weight loss maintenance. The American Journal of Clinical Nutrition, 82(1 Suppl), 222S-225S. Retrieved March 1, 2021, from


This article is prepared by Syamim Annisa Norzihan.

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