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Is Starvation Mode Real or Not?


On your weight loss journey, you may have come across the term “starvation mode.” But what exactly is starvation mode, and is it truly a scientific reality or another dieting myth? In this article, we talk about starvation mode, explore its legitimacy, and its effects on the body.


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What is Starvation Mode?

Starvation mode is a metabolic response that the body undergoes when it perceives a severe and prolonged calorie deficit. The idea is that when calorie intake is significantly reduced over a prolonged period, the body shifts into a survival mode where it slows down various physiological processes to conserve energy and maintain essential bodily functions.
The theory is that our bodies have evolved to find ways to stop us from losing weight when they sense that we aren’t getting as many calories as usual.

Is Starvation Mode Real?

There is an ongoing debate on whether starvation mode is a valid concept or not. Some argue that the body’s ability to adapt to reduced calorie intake is a well-documented phenomenon while others disagree. There is, however, some scientific evidence that shows that the body undergoes significant changes during long periods of low-calorie intake (*)(*)(*).

When Does Your Body Go Into Starvation Mode?

The body’s entry into starvation mode is not instantaneous; it’s a process triggered by prolonged and significant calorie restriction. Some scenarios that can lead to the activation of this metabolic response include:

  • Calorie restriction: Drastically reducing daily calorie intake over an extended period can lead to rapid weight loss. This can signal the body that it’s not receiving sufficient energy to maintain its functions which it perceives as being in starvation. This can, therefore, cause the body to go into starvation mode.
  • Crash diets: Extreme low-calorie diets, often referred to as crash diets, involve severe calorie reduction with the aim of rapid weight loss. These diets can also prompt the body’s survival response.
  • Chronic undernutrition: This triggers the body’s survival responses, including lowered metabolic rate, fat storage, muscle loss, hormonal shifts to conserve energy and maintain life during prolonged inadequate food intake.

How Do You Know When Your Body is in Starvation Mode?

Recognizing whether your body is in starvation mode can be challenging, as it’s not always accompanied by immediate and clear symptoms. However, some signs might indicate that your body is adapting to a reduced calorie intake are:

  • Stalled weight loss: If you initially experienced weight loss but noticed a sudden plateau despite maintaining a calorie deficit, your body might be adjusting its metabolism.
  • Low energy levels: Feeling persistently fatigued and having low energy levels, even after adequate sleep, could be an indicator of metabolic slowdown.
  • Feeling cold: Studies show that restricted calorie intake can lower your body temperature as it doesn’t have enough energy to keep you warm (*).
  • Alterations in hunger: An increase in appetite and hunger cues can be an indicator of starvation mode. During this state, the body raises your food cravings to increase your calorie intake. Starvation mode also leads to the production of hormones like cortisol and ghrelin which promote hunger (*).
  • Mood changes: Some individuals in a prolonged calorie deficit might experience mood swings, irritability, or difficulty concentrating.

What Happens When Your Body Goes into Starvation Mode?

During starvation mode, the body undergoes a series of physiological changes. In the absence of adequate energy intake, the body turns to muscle tissue for energy leading to a loss of lean muscle mass (*).

Fat stores, on the other hand, are preserved as the body recognizes them as a vital energy reserve. This metabolic shift is a protective mechanism that aims to ensure survival during times of limited food availability.

The body also reduces its basal metabolic rate (BMR), which is the energy expended at rest, to conserve energy (*). Moreover, the body becomes more efficient, using less energy during activities than it usually does (*).

Hormones that regulate appetite, satiety, and metabolism, such as leptin and thyroid hormones, may also be affected, altering the body’s response to calorie intake (*)(*).

Additionally, non-essential bodily functions are down regulated to prioritize vital processes, potentially leading to hormonal imbalances and disruptions to reproductive health (*). These changes are geared towards ensuring the body’s survival but can have implications for intentional weight loss efforts.


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Starvation Mode Myths vs. Facts

Several misconceptions surround the understanding of starvation mode. Below are some of the most common:

Myth: Starvation mode is an immediate response to skipping meals.

Fact: The body doesn’t immediately enter starvation mode due to short-term calorie deficits.

Myth: Starvation mode is the same for everyone.

Fact: Individual factors like genetics, body composition, and metabolic rate play a role in how the body responds to calorie restriction making the starvation mode experience unique for each person.

Myth: You can’t lose weight in starvation mode.

Fact: While weight loss might slow down, it’s not impossible. Strategic approaches that support metabolism and muscle preservation can still yield results.

How to Get Out of Starvation Mode

If you suspect that your body has entered starvation mode, here are some strategies that can help you reduce the effects of starvation mode:


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  • Resistance training: Incorporating strength training into your routine can help preserve muscle mass and maintain metabolic rate and strength (*)(*). You can perform resistance exercises such as lifting weights, squats, lunges, and push ups..
  • Adequate protein intake: High protein intake has been shown to reduce cravings, lower appetite, and increase metabolic rate (*)(*)(*). Protein consumption also supports muscle preservation which helps reduce metabolic slowdown (*).
  • Gradual calorie increase: You may temporarily take a break from your diet and increase your calorie intake. Increasing your calorie intake for a few days signals to the body that it’s no longer in a state of scarcity, potentially reactivating metabolism. Research shows that an increased calorie intake can temporarily increase hormones like leptin which are reduced during starvation mode (*)(*).
  • Prioritize sleep: Sleeping well can reduce the effects of starvation mode. Sufficient and quality sleep plays a role in hormonal regulation and metabolic health, promoting overall well-being (*).
  • Avoid extreme diets: Steer clear of crash diets and overly restrictive eating patterns, focusing on balanced nutrition to prevent prolonged metabolic adaptation.

The Bottom Line

Understanding starvation mode is crucial for making informed decisions about weight loss. Contrary to what some might think, weight loss after entering starvation mode is possible through strategies like resistance training and protein intake. Always remember that the key to long term weight loss is a healthy balanced diet that can still sustain your body despite being lower in calories. If you think you are doing everything right but you are still not losing weight, speak to a qualified health professional to design a new strategy that will help you achieve results.

20 References

Steinhauser ML, Olenchock BA, O’Keefe J, Lun M, Pierce KA, Lee H, Pantano L, Klibanski A, Shulman GI, Clish CB, Fazeli PK. The circulating metabolome of human starvation. JCI Insight. 2018 Aug 23;3(16):e121434. doi: 10.1172/jci.insight.121434. PMID: 30135314; PMCID: PMC6141167.

Dorling JL, van Vliet S, Huffman KM, Kraus WE, Bhapkar M, Pieper CF, Stewart T, Das SK, Racette SB, Roberts SB, Ravussin E, Redman LM, Martin CK; CALERIE Study Group. Effects of caloric restriction on human physiological, psychological, and behavioral outcomes: highlights from CALERIE phase 2. Nutr Rev. 2021 Jan 1;79(1):98-113. doi: 10.1093/nutrit/nuaa085. PMID: 32940695; PMCID: PMC7727025.

Watford M. Starvation: metabolic changes. eLS. April 2015:1-7. doi:10.1002/9780470015902.a0000642.pub2

Soare A, Cangemi R, Omodei D, Holloszy JO, Fontana L. Long-term calorie restriction, but not endurance exercise, lowers core body temperature in humans. Aging (Albany NY). 2011 Apr;3(4):374-9. doi: 10.18632/aging.100280. PMID: 21483032; PMCID: PMC3117452.

Tomiyama AJ, Mann T, Vinas D, Hunger JM, Dejager J, Taylor SE. Low calorie dieting increases cortisol. Psychosom Med. 2010 May;72(4):357-64. doi: 10.1097/PSY.0b013e3181d9523c. Epub 2010 Apr 5. PMID: 20368473; PMCID: PMC2895000.

Chaston TB, Dixon JB, O’Brien PE. Changes in fat-free mass during significant weight loss: a systematic review. Int J Obes (Lond). 2007 May;31(5):743-50. doi: 10.1038/sj.ijo.0803483. Epub 2006 Oct 31. PMID: 17075583.

Kosmiski L, Schmiege SJ, Mascolo M, Gaudiani J, Mehler PS. Chronic starvation secondary to anorexia nervosa is associated with an adaptive suppression of resting energy expenditure. J Clin Endocrinol Metab. 2014 Mar;99(3):908-14. doi: 10.1210/jc.2013-1694. Epub 2013 Dec 3. PMID: 24302748; PMCID: PMC3942230.

Rosenbaum M, Vandenborne K, Goldsmith R, Simoneau JA, Heymsfield S, Joanisse DR, Hirsch J, Murphy E, Matthews D, Segal KR, Leibel RL. Effects of experimental weight perturbation on skeletal muscle work efficiency in human subjects. Am J Physiol Regul Integr Comp Physiol. 2003 Jul;285(1):R183-92. doi: 10.1152/ajpregu.00474.2002. Epub 2003 Feb 27. PMID: 12609816.

Rosenbaum M, Nicolson M, Hirsch J, Murphy E, Chu F, Leibel RL. Effects of weight change on plasma leptin concentrations and energy expenditure. J Clin Endocrinol Metab. 1997 Nov;82(11):3647-54. doi: 10.1210/jcem.82.11.4390. PMID: 9360521.

Rosenbaum M, Hirsch J, Murphy E, Leibel RL. Effects of changes in body weight on carbohydrate metabolism, catecholamine excretion, and thyroid function. Am J Clin Nutr. 2000 Jun;71(6):1421-32. doi: 10.1093/ajcn/71.6.1421. PMID: 10837281.

Martin B, Golden E, Carlson OD, Egan JM, Mattson MP, Maudsley S. Caloric restriction: impact upon pituitary function and reproduction. Ageing Res Rev. 2008 Jul;7(3):209-24. doi: 10.1016/j.arr.2008.01.002. Epub 2008 Feb 7. PMID: 18329344; PMCID: PMC2634963.

Chomentowski P, Dubé JJ, Amati F, Stefanovic-Racic M, Zhu S, Toledo FG, Goodpaster BH. Moderate exercise attenuates the loss of skeletal muscle mass that occurs with intentional caloric restriction-induced weight loss in older, overweight to obese adults. J Gerontol A Biol Sci Med Sci. 2009 May;64(5):575-80. doi: 10.1093/gerona/glp007. Epub 2009 Mar 10. PMID: 19276190; PMCID: PMC2800807.

Hunter GR, Byrne NM, Sirikul B, Fernández JR, Zuckerman PA, Darnell BE, Gower BA. Resistance training conserves fat-free mass and resting energy expenditure following weight loss. Obesity (Silver Spring). 2008 May;16(5):1045-51. doi: 10.1038/oby.2008.38. Epub 2008 Mar 6. PMID: 18356845.

Leidy HJ, Tang M, Armstrong CL, Martin CB, Campbell WW. The effects of consuming frequent, higher protein meals on appetite and satiety during weight loss in overweight/obese men. Obesity (Silver Spring). 2011 Apr;19(4):818-24. doi: 10.1038/oby.2010.203. Epub 2010 Sep 16. PMID: 20847729; PMCID: PMC4564867.

Weigle DS, Breen PA, Matthys CC, et al. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. The American Journal of Clinical Nutrition. 2005;82(1):41-48. doi:10.1093/ajcn/82.1.41

Veldhorst MA, Westerterp-Plantenga MS, Westerterp KR. Gluconeogenesis and energy expenditure after a high-protein, carbohydrate-free diet. Am J Clin Nutr. 2009 Sep;90(3):519-26. doi: 10.3945/ajcn.2009.27834. Epub 2009 Jul 29. PMID: 19640952.

Soenen S, Martens EA, Hochstenbach-Waelen A, Lemmens SG, Westerterp-Plantenga MS. Normal protein intake is required for body weight loss and weight maintenance, and elevated protein intake for additional preservation of resting energy expenditure and fat free mass. J Nutr. 2013 May;143(5):591-6. doi: 10.3945/jn.112.167593. Epub 2013 Feb 27. PMID: 23446962.

Poehlman ET, Tremblay A, Fontaine E, Després JP, Nadeau A, Dussault J, Bouchard C. Genotype dependency of the thermic effect of a meal and associated hormonal changes following short-term overfeeding. Metabolism. 1986 Jan;35(1):30-6. doi: 10.1016/0026-0495(86)90092-2. PMID: 3510362.

Dirlewanger M, di Vetta V, Guenat E, Battilana P, Seematter G, Schneiter P, Jéquier E, Tappy L. Effects of short-term carbohydrate or fat overfeeding on energy expenditure and plasma leptin concentrations in healthy female subjects. Int J Obes Relat Metab Disord. 2000 Nov;24(11):1413-8. doi: 10.1038/sj.ijo.0801395. PMID: 11126336.

Koren D, Dumin M, Gozal D. Role of sleep quality in the metabolic syndrome. Diabetes Metab Syndr Obes. 2016 Aug 25;9:281-310. doi: 10.2147/DMSO.S95120. PMID: 27601926; PMCID: PMC5003523.


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