What is this?

In theory, it is a really simple dieting plan. Why simple? This is simple because it eliminates the need to choose what to eat; all you need to do is determine when to eat. Basically, you have a window on every day to see when you eat and when you don't eat.

There are quite a few variants of this diet plan.

Alternate-day fasting: on one day, you eat a normal diet, and on the second day, you eat a very restrictive diet (500-600 calories a day). On paper, it sounds good; however, some hazards may occur. The primary concern is that this diet does not eliminate the risk of overeating. If, as an average male, you require 2500 kcal per day, and you consume 5000 kcal one day and only 500 kcal the next, you will not lose weight. It's more likely that you'll end up gaining weight. Therefore, if you don't pay attention to overeating and what you're eating on your non-fasting day, it could lead to depression and a decision to quit the diet.

5:2 fasting: again You should fast for 5 days, and then take a break for 2 days. On fasting days, you should eat only 500-600 calories, so it should only be one meal a day. Oh, boy… Going without food for two days can be challenging. Again, consuming 3500 or 5000 calories a day for 5 days won't prevent you from starving yourself on the weekend.

Finally, each day, eating was restricted. You can eat for 8 hours every day, but not for 16 hours. This model is the most popular and may benefit the most people. Secondly, this model is easily achievable due to the availability of numerous mobile phone apps, and it's easy to remember that you can eat from 10 AM until 6 PM. Have I done it? Yes. Did I quit? Yes. Why? It becomes frustrating when you are not able to replenish your energy with some food. For example, you can eat from 10, but your job starts at 7. That means you need to be able to eat at 10. If you have tasks to complete at that moment, it's easy to forget about eating and become extremely hungry. Being hungry led to extreme exhaustion and fatigue, as well as the onset of severe headaches. This was the primary reason I decided to stop eating.

On some main web pages, you can find information that intermittent fasting may help to reduce inflammation and diseases associated with inflammation, such as Alzheimer's disease, arthritis, asthma, multiple sclerosis, or stroke (atherosclerosis).

So does it work?

Let’s look what PubMed says:

From 27 studies included in the analysis, a systematic review by Welton et al. (1) showed that participants lost weight from 0.8% to 13% without experiencing any serious adverse events. Five studies demonstrated the effectiveness of this diet type in controlling glycemia in individuals with type 2 diabetes. However, when we compared this diet type with a typical calorie restriction diet, we found no significant differences.

A next systematic review from Spain (2) showed that it helped to control blood lipids, improved glycemia control, and may be a safe approach to losing weight for people with multiple sclerosis. Will it help to control multiple sclerosis? The review does not address that.

Lastly, a meta-analysis by a Chinese scientist showed that intermittent fasting helped to lose more weight than a continuous calory restriction diet; however, body mass index (BMI) did not significantly differ among these groups (3).

These three studies conclude that all conducted studies are small, and in the scientific realm, large randomised controlled studies (the best multi-centre studies) are necessary to confirm the superiority of one method over another.

So here are some tips for you to achieve weight loss: set clear, achievable goals, plan meals in advance, and keep healthy snacks handy. Track your progress using a food diary or an app, monitor your weight, control portion sizes, and eat mindfully. Stay hydrated by drinking plenty of water throughout the day. To avoid temptations, remove junk food and find healthier alternatives. Seek support from friends, family, or a support system. Manage cravings by satisfying them with healthier options and waiting for them to pass. Stay active by incorporating regular exercise into your routine and choosing fun activities. Be flexible, allowing occasional treats and adjusting your diet as needed. To make healthier meals at home, educate yourself on nutrition and cooking skills. Maintain a positive mindset by celebrating successes and learning from setbacks. Remember to stay motivated and adapt to your new routine.

Lastly, does intermittent fasting work? Yes, it works. Does it work better than any other dieting plan? There is no clear evidence for that. Will it work for you? Possibly yes, if you remain motivated and on track. Best luck in your dieting journey.

References:

1.            Welton S, Minty R, O’Driscoll T, Willms H, Poirier D, Madden S, et al. Intermittent fasting and weight loss: Systematic review. Can Fam Physician Med Fam Can. 2020 Feb;66(2):117–25.

2.            Giménez Lozano JM, Martínez Ramón JP, Morales Rodríguez FM. Doctors and Nurses: A Systematic Review of the Risk and Protective Factors in Workplace Violence and Burnout. Int J Environ Res Public Health. 2021 Mar 22;18(6):3280.

3.            Zhang Q, Zhang C, Wang H, Ma Z, Liu D, Guan X, et al. Intermittent Fasting versus Continuous Calorie Restriction: Which Is Better for Weight Loss? Nutrients. 2022 Apr 24;14(9):1781.