Intermittent Fasting and Weight Loss

People use many different methods to lose weight. In recent years, one approach has gained a lot in popularity — intermittent fasting. 

But what is intermittent fasting? How does it work? And most importantly — is it a useful weight loss technique? [1]

Intermittent Fasting Explained

Intermittent fasting is a weight loss technique which involves regular, short-term fasts. Short fasts have already proven to be effective for health, but it also has a significant influence on specific weight control hormones which I will talk about.

There are four popular methods of intermittent fasting:

  1. Eat Stop Eat method which involves completing one or two 24 hour fasts each week, meaning that you don’t eat at all for a 24 hour period.
  2. 16/8 method that consists of skipping breakfast and eating within a specific 8 hour period.
  3. 5:2 method that involves eating only around 500 or so calories two days a week and eating regularly in the remaining five days.
  4. The Guerrilla Diet recommended intermittent fast: Eat everyday for 10-12 hours and fast everyday for 12-14 hours. This is how our ancient ancestors lived on the savanna grasslands of Africa where there is darkness for 12 hours of the day. By the time they reached new food resources in the morning, at least one hour would pass, and in the night, while preparing for sleep, at least one hour would pass before sleeping. All together, ancient humans regularly fasted for 12-14 hours and sufficiently rested during the night.

Effect on Hormones

When you eat less, your body finds other ways for making the stored energy more accessible. Your body will breakdown fat stores for energy production. But there are also several hormonal changes which occur within your body which effectively cause weight loss:

Your insulin levels decrease when you fast, and lower insulin levels cause fat burning.

Your levels of human growth hormone decreases dramatically during fasting and this hormone aids in fat loss and muscle gain.

Also, noradrenaline levels rise in the blood during fasting. This stress hormone increases focus and alertness but it also releases fatty acids from fat cells which leads to increased fat burning.

Short-term fasts including The Guerrilla Diet recommended intermittent fast, have shown to burn fat much faster because they boost metabolism up to 14%. [2-4] However, more extended fasting periods have an opposite effect — they actually suppress metabolism. [5-6]

Reducing the Intake of Food

One of the main effects of intermittent fasting is undoubtedly that it lowers your intake of food. Every periodic fasting method involves a break from meals, so you will ingest a lot less food than usual. [7]

An older study [8] has shown that intermittent fasting reduces body weight by 3-8% during a period of up to 24 weeks.

How to Use Intermittent Fasting to Lose Weight

As you can see, intermittent fasting does have several significant effects on weight loss. However, you need to implement the technique properly for it to have an effect.

First of all, Intermittent fasting is an approach that should be combined with a change of diet in order to provide the ideal health benefits that our bodies are primitively used to, for health and natural weight loss.

Secondly, intermittent fasting does not include drinking water which is allowed throughout the fasting period. However, it is not necessary to drink water during the fasting period unless thirst is felt.

To conclude:

Intermittent fasting is a healthy approach that not only clears the body but also allows to clear the mind, since the period of not eating slows down the body’s digestive processes and helps relax the constant chattering of the mind. 

Have patience with yourself and with your body. Intermittent fasting takes some time getting used to, but if you maintain this regimen and you are consistent, you will not only see the health benefits within a few weeks, you will also notice significant weight loss.

References:

[1] Johnstone A. Fasting for weight loss: an effective strategy or latest dieting trend? Int J Obes (Lond). 2015 May;39(5):727-33. doi: 10.1038/ijo.2014.214. Epub 2014 Dec 26.

[2] Webber J, Macdonald IA. The cardiovascular, metabolic and hormonal changes accompanying acute starvation in men and women. Br J Nutr. 1994 Mar;71(3):437-47.

[3] Mansell PI, Macdonald IA. The effect of starvation on insulin-induced glucose disposal and thermogenesis in humans. Metabolism. 1990 May;39(5):502-10.

[4] Zauner C, Schneeweiss B, Kranz A, Madl C, Ratheiser K, Kramer L, Roth E, Schneider B, Lenz K. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. Am J Clin Nutr. 2000 Jun;71(6):1511-5.

[5] Müller MJ, Enderle J, Pourhassan M, Braun W, Eggeling B, Lagerpusch M, Glüer CC, Kehayias JJ, Kiosz D, Bosy-Westphal A. Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited. Am J Clin Nutr. 2015 Oct;102(4):807-19. doi: 10.3945/ajcn.115.109173. Epub 2015 Sep 23.

[6] Nair KS, Woolf PD, Welle SL, Matthews DE. Leucine, glucose, and energy metabolism after 3 days of fasting in healthy human subjects. Am J Clin Nutr. 1987 Oct;46(4):557-62.

[7] Harvey J, Howell A, Morris J, Harvie M. Intermittent energy restriction for weight loss: Spontaneous reduction of energy intake on unrestricted days. Food Sci Nutr. 2018 Feb 21;6(3):674-680. doi: 10.1002/fsn3.586. eCollection 2018 May.

[8] Barnosky AR, Hoddy KK,  Unterman TG, Varady KA. Intermittent fasting vs. daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Research. 2014 October; 164(4):302-311

[9] Antoni R, Johnston KL, Collins AL, Robertson MD. Intermittent v. continuous energy restriction: differential effects on postprandial glucose and lipid metabolism following matched weight loss in overweight/obese participants. Br J Nutr. 2018 Mar;119(5):507-516. doi: 10.1017/S0007114517003890. 

[10] Mansell PI, Fellows IW, Macdonald IA. Enhanced thermogenic response to epinephrine after 48-h starvation in humans. Am J Physiol. 1990 Jan;258(1 Pt 2):R87-93.

Leave A Response

* Denotes Required Field